Disclaimer: I own neither One Piece or Highschool DxD.

The Immortal King

"I'm gonna be the Harem King!"

Rias truly loved her servant Issei. He was passionate, courageous and a hard worker. No one could deny his good qualities once they got to know him. Especially after the lengths he went to save her from the arranged marriage to Riser Phenex. But even she couldn't help but feel a bit tired of hearing him parade his perversion around so easily. His pursuit of multiple women, while a good motivator, could wear on anybody. Especially the girl that was interested in him that way. Rias might have been willing to share him someday, but it wasn't a fun topic to discuss.

So she decided to toy with him a bit.

"That goal might not be as easily attained as you think, Issei," Rias said, drawing her peerage's attention, specifically her pawn, to her. "There are plenty of men in Hell-no-in all the realms that possess rather large harems. Many with quite beautiful women."

"That's fine. My goal for a harem is about getting the best girls, anyway! Though that doesn't mean I won't try for the most, either." Issei chuckled confidently, eliciting a small blush from Rias. But despite herself, she didn't give up on her plan.

"I see. But to do that, you'd have to surpass the Immortal King's harem." Rias suggested, causing Issei to blink in question.

"The Immortal King?"

"Does that count, though?" Akeno asked, touching her chin in thought. "It's true that many of the most beautiful women in the world are in love with him, but…"

"W-wait! So this guy is the true Harem King?! How?! Why?!" Issei asked in desperation, a small amused smile spreading across his master's lips.

"It is not in volume that the Immortal King would be so, but who he's bewitched with his charm that he has earned the title," Rias explained with some mischief, causing the brunette to sweat nervously.

"Wh-who then?! It can't be that difficult to overcome! I'll do it in a heartbeat!" Issei exclaimed, earning a chuckle from Kiba.

"That might be a taller order than you expect, Issei-kun. The first woman to fall in love with the Immortal King was none other than Gabriel, the most beautiful Angel in Heaven," The knight explained, though apparently catching on to what his master was doing.

"Then there's the Youkai Queen of Kyoto, Yasaka. Her beauty and power rival that of any Ultimate-Class Devil." Akeno supplied this time, finding a bit of fun in teasing the brunette now as well. "If you saw her, I'm sure you'd be quite jealous, Issei."

"Let's not forget an even closer acquaintance to us all, Serafall Leviathan, Sona's older sister," Rias declared, causing Issei's jaw to drop.

"W-wait, what?! No way! Even Sona's older sister?!"

"That's right. Though Sona said that he's a bit too carefree for her taste, she could admit to seeing what allured many women to him as well."

"There's a rumor going around that one of the Five Dragon Lords, Tiamat, is also in love with him," Xenovia said this time, surprising the group with her knowledge on the subject. "The Immortal King was the subject of much talk considering his stance of neutrality despite the many relations he built up over time."

"It sounds like he has some of the best chicks from every faction!" Issei blanched in shock, biting his bottom lip in discouragement."I guess I'll have a tougher road ahead of me than I thought…"

Rias giggled before standing up and touching her servant's shoulder in reassurance, having had enough fun teasing him. "Don't worry, Issei. I'm sure you'll be able to compete someday in the future. Besides, you have one distinct advantage over him."

"I-I do? What's that?" Issei asked as hope returned to him.

"The Immortal King hasn't accepted any of them as his wives." Rias declared, Issei now gawking at the revelation as his master began to laugh. "I'm sorry, Issei, I was merely teasing you earlier. In truth, the Immortal King has little to no interest in taking any brides. He likes to travel around freely without being pinned to one place. But it is true that all of the women we mentioned have fallen in love with him."

W-wait, really?! What a waste!" Issei exclaimed in disappointment before narrowing his eyes. "But even so… I don't know if I'd be able to accept the title of Harem King by default just because of that…

"As determined as ever to prove himself." Akeno giggled.

"Maybe one day, I'll get to meet him and convince him of the true beauty of breasts!" Issei continued, holding his chin in thought. "So why's he called the Immortal King, anyway?"

"Oh, that? Because, plainly put, he's immortal but hails from no known faction. His immortality wasn't by choice, either. Aside from a strange power to stretch like rubber, most have determined that he's perfectly human," Rias explained, causing Issei's eyes to widen in surprise. "But there's one distinct difference between him and regular humans: he comes from a different universe."

"Wait… what?"

"Cool. Looks like we're here."

In the mountainous realm of Jotunheim, a lone boy stood at the foot of a stone stronghold. Its walls were integrated with the mountain, an ancient language written across its walls that the boy couldn't be bothered to attempt reading. He stood at five foot eight inches tall, his skin lightly tanned and the bed of hair on his head raven black that was covered by a straw hat. His eyes were dark brown and underneath the left lid was a small scar. He wore a red long sleeve cardigan that opened at the chest, revealing a large scar in the shape of an 'X' on his chest. Despite the scar, a body of muscle could be seen behind it, his figure well toned despite his lankiness. He wore blue jean capris shorts and wooden sandals on his feet. A yellow sash wrapped around his waist as well as an oversized traveling bag on his back.

"Are you sure this is the approach you want to take, brother? I'm sure there are several ways we can go about this more tactfully."

Looking down at his waist, Luffy pulled a severed head tied to his sash up in front of him to look at it. It had been the source of the voice, despite lacking its own body. The head was clearly male, looking aged with a long dirty brown beard and horns on his forehead. His eyes illuminated yellow, looking like jewels rather than actual eyes.

"What's wrong with asking for it back?"

"Look, I know you have a few Giant friends Luffy, but not all of them would feel so inclined as to just hand over the hammer of Thor. Especially not the son of Thrym," The head answered, expressing as much logic as he could for the boy to understand. "If anything, we should try and sneak inside to steal it back. You may not be the most stealthy person, but I'm sure with my guidance, we can manage."

Luffy tilted his head to one side in thought, considering his strange companion's request. With a large grin, Luffy shook his head. "Nah, it'll be fine Mimir. If he doesn't wanna give it back, I'll just fight him for it."

The severed head released a heavy sigh, which he likely would have shook if he still had a body. "I guess this won't be one of the days I convince you to take the more logical route. Have it your way."

"Maybe next time," Luffy chuckled with a toothy grin, stretching his arm out and reaching for the giant knocker on the gates. With several thunderous thud, the gates shook. "Oi~! Anyone home right now?! I'm Monkey D. Luffy! I'm here to take Thor's cool hammer back!"

Retracting his arm, Luffy placed the severed head back on his sash, crossing his arms as he waited for an answer. "Huh. Maybe he's not home."

"After stealing Mjolnir, I doubt he'd be anywhere else," Mimir hummed. After another moment passed, the stone doors creaked with life, scraping across the earth they receded back into the mountain. From the darkness within, A giant blue being stepped out from the other side, a towering Jorgun now stooping over Luffy and Mimir. He couldn't have been shorter than one hundred meters, His body an ice blue and his skin as rough as the mountain he stood under. He wore a ragged loincloth and best, fangs sticking out of his lower jaw and his eyes yellow.

"You… you're no Asgardian," The giant rumbled out, his voice booming as he spoke. "And I don't see my demanded gift."

"Sorry, but old man Odin said that you were asking for too much. I just came here to take it back so that no war breaks out over it," Luffy explained, casually crossing his hands behind his head.

"You come to my domain with nothing to offer? Demanding that I hand over the mighty Mjolnir for nothing?! You dare show such disrespect?!"

"You're lucky that you're getting this much, you twit. If it wasn't for Laufey asking the lad to be nice, you'd be fighting right now! You couldn't just learn from your father's mistake the first time 'round and leave well enough alone," Mimir huffed, his glowing eyes glaring up at Thurm in disappointment.

"I deserve my revenge! My father fell at the hands of Thor, at a wedding planned for him and the Goddess Freya, no less!" The Giant roared furiously, his breath creating a gust as he spoke and filling the air with a foul stench.

"Then why'd you ask for a wife?" Luffy asked bluntly, a brow raised. "If you wanted to fight Thor, just do it."

"Th-that's not the point! I want to embarrass the Asgardians the same way they embarrassed me! And with the seals in place around my home, they'll never be able to come in swinging," Thurm laughed boisterously, earning a small sigh of disappointment from Mimir. "To take Thor's wife from him in exchange for his mighty weapon is the ultimate revenge!"

"If only you had picked up your father's intellect instead of his perversion. You likely would have risen up to be a King like he was. Look Thurm, there's a stable peace between Jotunheim and Asgard, one that's existed for hundreds of years now. That doesn't need to be jeopardized because you want to bed Lady Sif," Mimir said, Luffy holding his head up to allow him to speak.

"Silence! Your words mean nothing to me! If you cannot provide my ransom, then the hammer of Thor belongs to me now!" Thurm declared, keeping his feet planted behind his doors. "You can't come in and the runes will keep you at bay!"

"Actually, brother, those runes only ward away Asgardians and Valkyries. They don't do a lick of anythin' to hold back the boy, here," Mimir informed him, causing the Giant to blink in shock.

"So, I guess we're fighting then," Luffy said, spinning his arm around to stretch it out. Thurm echoed with laughter despite his words, grinning down at Luffy.

"So what if he can? I'll just crush him and send you both back as a message to-"

Thurm didn't get a chance to finish his sentence, Luffy disappearing from his sight before reappearing right in front of the Giant's face. His fist shifted in color to a jet black, shining like polished metal. Steam rose from his body that had turned a shade of pink.

"Oh…"

"Bullet!" With a thunderous smack, Luffy smashed his fist right into Thurm's jaw. Despite the obvious difference in size, the punch was strong enough to reverberate through Thurm's entire body, the punch breaking several of his teeth and almost snapping his jaw. The Jorgun blacked out for a quick moment, falling into his stone doors and collapsing them under his weight. He rolled forward, falling out of the safety of his home and into the earth and grass of the mountain he occupied.

"And here I thought you'd hold back a bit on the lummox. Not that he didn't have that coming," Mimir half chuckled, looking down at the Giant as Luffy fell back toward the ground.

"I did, though. I was just trying to knock him out," Luffy said with a shrug as he landed feet first on the dirt.

"Well, it might have been better to leave him conscious. We still need to find the hammer inside, after all. I imagine his home is quite large," Mimir reasoned, causing Luffy to widened his eyes.

"Oh yeah, I guess you're right!" He exclaimed before looking back at Thurm's form. The Giant groaned in pain, slowly placing his hands on the ground to push himself up. "Hey, he's awake! Looks like he can still tell us!"

"Y-you… I'll kill you, damn it!" Thurm snapped, raising an arm and swinging it at Luffy.

The rubber boy quickly jumped over the behemoth's arm, swinging his leg up behind him. "Gomu-Gomu no… Stamp!" winding it back, Luffy unleashed it forward and planted his sandal straight into Thurm's gut. The Jorgun's eyes rolled back in pain, the air leaving him as he buckled over in pain. Luffy landed on top of Thurm's shoulder, looking down at the Giant with a neutral expression.

"Hey, can you tell me where the hammer is? I wanna get back to Asgard already. Old man Odin said he'd give me a feast for bringing it back!" Luffy explained, placing his hands on his hips as he waited for the giant to answer.

"Thurm, do yourself a favor and tell the boy. We get the hammer and everyone walks away from this. No war between Jotunheim and Asgard and you're spared any further consequences. Make it easier on yourself," Mimir advised out of pity, releasing a sigh as he hoped the Giant would listen to reason now that he was on the ground and beaten.

"... I-it's… in the furthest most chamber to the right… just take it and go…" Thurm mumbled out, groaning as he massaged his stomach.

"Alright, thanks!" Luffy smiled before hopping off, following the Giant's instructions as he went inside the stronghold. It didn't take long before Luffy found the hammer, a grin spreading wide across his face. "Oh man, it looks so cool! It's huge, too!"

"Now careful, lad. Remember that if your heart isn't pure or free of dark desires, it'll be-" Mimir began to warn, only for Luffy to stretch his arm out and grab the handle, quickly pulling it to himself. He blinked, waving it around like it weighs nothing.

"Hey, it's really light!"

"... I guess that doesn't surprise me much," Mimir sighed in amusement, watching as Luffy waved it around to test its weight. "We should get goin'. No doubt the dobber is lickin' his wounds outside."

"Got it. Hey, will this make me fly?" Luffy asked, holding it up in the air in hopes of being carried off the ground.

"Sorry, lad. Among the many powers the hammer gives, flying isn't one of them. Thor would wrap the pommels band around his wrist and twirl it before throwing to carry him off the ground."

"What?! That's lame!" Luffy exclaimed in disappointment, sourly placing the hammer on his back and tying it there.

"Don't tell Thor that. He might take some offense," Mimir chuckled in response, the boy and the head now heading for the exit. Thurm was still there leaning against the frame of his stone doors, nursing his jaw and stomach.

"Alright, I'll see you later Thumb! I'm gonna take this back to Asgard!" Luffy said, waving to the bruised Jorgun as he walked by him.

"Wh-who are you? Why did you come in place of the Asgardians?" Thurm asked, looking down at the strange boy in question. Luffy halted before looking back up at him, his gaze causing Thurm to regret his question at first.

"They're my friends, that's all. Old man Odin asked me to come so that they didn't cause any trouble for the other Giants. Plus he said he'd give me a banquet as a reward!" Luffy answered easily, giving Thurm one last grin before turning back to his path.

"Try to remember this for future reference, Thurm. Stirring up trouble because of ancient history doesn't solve any problems." Mimir said, his head now dangling from Luffy's hip again. "And please, learn from your father's mistake. Think with your brain, not with the organ of your nether regions."

"Yeah…"

"That went well, all things considered," Mimir said, humming in thought. "Plan to go straight back to Asgard then?"

"Yeah. I was gonna mess around with the hammer, but since I can't use it to fly I'm not interested," Luffy said, puffing his cheeks out childishly at the disappointing discovery.

"Brother, you've got the power of an Aesir god in your hands, and your only concern is the inability to fly?" Mimir asked, breaking out in a fit of laughter. "Goodness, you can always be so simple."

"Oi~! I'm back!"

An eruption of greetings and praise echoed through the halls of Asgard, many welcoming the rubber boy with open arms. As if predicting his return that same day, the halls were already set with tables and platters of meat and barrels of mead. The smell of freshly roasted meats, ranging from boars to great bison, filled the air, immediately drawing Luffy inside to receive his reward.

"It looks like you've arrived just when I predicted. Feel free to dig in at your leisure, Luffy." Odin, an elderly man at the head of the room laughed. He had a long white beard that stretched down to his feet and wore a blue robe. A spear stood by his side, being the great weapon Gungnir.

Of course, the rubber boy hadn't bothered to wait for his approval, already ripping the leg off a roasted boar and biting into the meat. "Thabks, olb mabn!" He said, his words muffled by food in his outstretched cheeks.

"Make sure to pour me some mead when you get the chance, brother. Bein' your traveling companion can be thirsty work for a severed head," Mimir chuckled from Luffy's hip, the straw hatted boy quickly pulling him off and setting him down on the table so that he was part of the banquet. He quickly stretched an arm out and filled a cup full of the ale provided for the party, placing it in front of Mimir before a server brought a straw for him. Taking some sips of his drink, the severed head let out a hearty breath.

"Ah~, now that's the stuff. No stomach, yet ale tastes and feels as lovely as ever. Oh, by the by, don't forget to give the hammer back."

Luffy grabbed the hammer off his back and tossed it to the front of his throne while working on his meal, causing some in the room to flinch in fear, but thankful when it fell at Odin's feet without any damage done.

"It's always the same reward for you. Banquets and enough gold to get you by. You could always try asking for something more wholesome, Luffy." Odin chuckled, shaking his head before looking to his left.

Standing close to his throne was a young woman with long, beautiful silver hair that stretched down to her feet. She wore the accustomed Valkyrie armor of a silver and black breastplate, silver gauntlets and matching steel plated boots underneath silver hip guards. She watched the young man intently, knowing him quite well like most others in the halls of Asgard.

"You should broaden your horizons. Perhaps consider taking a wife or mistress to liven things up. Rossweisse here is available and in desperate need of a lover." Odin smiled teasingly, reaching forward and slapping his personal guard on the butt to knock her forward.

"E-eh?! You-your majesty! What are you saying?!" Rossweisse cried out in embarrassment, her cheeks becoming rosy as she pouted at her liege. "Y-you don't have to tell him that!"

"Come now, this might be a good chance for you. I doubt you'll find a better lover than the Immortal King," Odin whispered to the Valkyrie, causing Rossweisse's blush to intensify at the implication. "Besides, you've had your eye on him for some time, right?"

"W-well I-"

"No thanbs." Luffy muffled out again before swallowing all of the food in his mouth. "Phew. No thanks. I'm not a dirty old man like you." Luffy bluntly taunted with a toothy grin, roars of laughter breaking out from the Aesir gods of the hall. Even Rossweisse let out an amused giggle, despite indirectly being rejected by the rubber boy.

"As blunt as always with his words," Odin sighed, shaking his head before standing from his throne and holding a cup up. "But let us have a toast! To the Immortal King, Straw Hat Luffy! Thanks to his intervention, peace shall continue with the Jotunar!"

"Here here!" The many gods of the court cheered, raising their cups in honor of Luffy. The rubber boy merely grinned, letting out a small laugh in appreciation.

Sitting back in his throne, Odin allowed the festivities to continue. "So, Luffy. Will you be staying with us for a little longer or will you be moving on soon again?"

"I'm gonna leave tomorrow," Luffy answered, drawing a small frown from Rossweisse at hearing so. "Zechs asked me to drop by when I had the chance. Guess he wants to talk about something."

"I see. Quite a bit has been going on in the past few months with the Three Factions. I'm quite curious as to what he might ask of you as well," Odin hummed in interest before shifting his gaze to the severed head next to Luffy. "What of you, Mimir? You've been traveling for quite some time with Luffy. Will you continue to do so?"

"Aye, your majesty. I'm quite enjoying my little adventures with the lad. Besides, someone has to make sure he doesn't get lost in some godforsaken realm," Mimir chuckled, earning a smile from Luffy.

"Thanks for that. I'd be stuck in a forest without you," Luffy admitted without shame, earning a resounding laugh from the court. Despite Luffy's prowess in a fight, many were aware of his poor sense of direction and tendencies to get lost.

"It seems that you were both fated to stay together, then. You have my blessing, I only wished to see if you wanted to return," Odin chuckled, welcoming the severed head's choice. "Come then, my fellow Aesir! Let us give our guests the banquet they deserve!"

"Aye!"

To be continued…

Alright, let's get this out of the way right off the bat: This is not a full length/long running story like others I've written. This is merely a series of one-shots/short stories revolving around Luffy's adventures through the DxD world. That's not to say they won't all be interconnected, as certain themes and ideas will recur throughout the series. But know that it's more about the adventures that Luffy has had both in the present time and in the past.

With that said, chapters can be rather short like this one was or perhaps long, if I feel like it. This won't be a story I update in a timely manner, it's a side story that I'm going to be working on for fun. I've got more linear stories I'm writing that are much longer than this will be and have my primary focus.

(Speaking of which, sorry to any of the readers of my other stories. Sorry, this one was just stuck and my head and needed to be put out lol I've begun the work on the next chapter of ADD, so don't worry.)

And before you say anything, yes, I did take Mimir from God of War (who is an actual figure in Norse Mythology anyway) and give him to Luffy as a traveling companion. Why? Because one, I recently got into the game and loved it and loved Mimir as a character. And two, we all know how hopeless Luffy can be without someone to help him to keep track of where he's going. Mimir seemed like the perfect candidate. Some might argue that it would be best to place a woman who is in love with Luffy in this place, but to be honest I liked the dynamic that this relationship could have. Plus, Luffy may or may not get more traveling companions anyway. Who knows.

Now, considering the nature of this story though, I'm welcome to receive ideas from anyone willing to share about how Luffy came to meet any of the other women in DxD that come to fall for him. If it's good enough, I may even write it out and post it as a chapter. Just be sure to PM me with the idea or leave it in the review section, either one works.

Now, since this isn't a truly serious story, I'd be happy to let anyone take the wheel on this one if they wanted. I have an idea of the overall arching story around Luffy's arrival and his presence in the world, so I am willing to share that and bounce ideas with anyone who's willing to take the helm. Other than that, do enjoy what I do end up writing here, whatever it is.

Well, that's that. Please feel free to leave a review and tell me what you think. If you have any of the women in DxD that you'd like to see get some sort of chapter or to fall for the oblivious guy, feel free to say so and perhaps leave an idea. Until then, have a good one!