Alright guys I'm doing this story because no one else hasn't thought up this one for some goddamn reason! I mean come on we have Mass Effect and Overlord crossover's and no one could think to connect these two?

So wit that said let's get this story started!

*Clang* *Clang* *Clang* rang the sound of metal on metal as blade met blade.

The room itself was more like a circular cavern where a large throne draped in red sat at one end while the other stretched out towards a small platform. In the center lay a circle blue glowing stone's slightly sinking downwards while around it was grey and black stone. Yet all throughout the room were streams of lava flowing freely and unimpeded thanks to the rooms natural structure.

Despite the room's unique and downright evil structure it was of little notice to the rooms occupants. Near the throne stood three women of great beauty, the first was dressed in simple, yet elegant, medieval peasant's wear of a black bodice over a white shirt and a red cloth falling over her white skirt that fell to her ankles with pale brown skin and short red hair that curled at the ends her bright green eyes focused on the center of the room. This was Kelda, a huntress from the northern village of Nordberg.

Next to her was another beautiful woman but she was a far contrast to the simple village woman. For one her attire was similar to that of a white roman toga tthat draped over her left shoulder and fell down to her ankles while it also displayed a generous amount of cleavage and a slit down the left leg. Unusually she also had on a bronze chest plate that was showcased and her left side with matching arm and wrist bands. Her skin was slightly darker than Kelda's and her dark brown hair was longer, falling to mid back in a mixture of wave and curl's while her chocolate brown eyes gazed at the center of the room like Kelda only her eyes showed some amusement and a hint of lust. Her only other accessory was the circular earing's she wore. This was Juno, a temptress that was once a citizen of the Glorious Empire and the desire of every man in it.

The final woman of the three was by far the most elegant of them all and dressed like royalty. Her outfit was a mixture of darker shades of purple that bordered on black. The dress looked as if it was made of a combination of leaves and vines with a small flair behind her head. Her skin was pale red while her hair was a darker, more crimson red and neatly done up to fall to her shoulders. Her pale grey eyes looked almost bored at the display happening before her but still she watched on with undivided attention. This was Fay, or Dark Fey as she is usually called, the former Queen of the elves and a being of light magic who had long since turned to the darker side of things.

Finally around the entire room was a collection of small impish creatures ranging in a multitude of colors of brown, red, blue and green. Next to the three women however stood an old grey minion in a cloak and had a stick hanging over him with a lantern tied on the end. This was Gnarl, advisor for the Overlord and senior Minion. While Gnarl gazed on with a savage fang-filled grin the rest of his fellow minions were hooting and hollering at the spectacle happening in the center.

What was the sight? It was fight to the death that originally started with several against one but now had been riddled down to a one on one match. The first figure appeared to be some type of knight standing at average height and clad in silver plate armor and blue cape and wielding a straight sword. His skin was fair, almost pail and was dripping with sweat that matted his once fluffy blonde hair to his head. His crystal blue eyes were filled with fear and desperation as he fought back against his overwhelming foe.

Said foe was in all words a demon. He stood a little over seven feet tall and was well muscled while being covered in ebony black armor with the image of a trident emblazoned on the chest piece. The armor itself was spiked and the helmet had a large trio of spikes on the helmet serving as a makeshift crown while a lack cloth covered the rest of his face. In his right hand he brandished a large, glowing bronze, leaf shaped blade that was nearly as large as himself and over a foot wide at it's widest point. Despite the mans great size he was immensely fast to match the strength his form showed. The feature about him that stood out the most however was the two glowing green pools of fire that glared down at the smaller man in amusement. This being was the Overlord, Master of the Dark Tower, destroyer of the Glorious Empire and Ruler of the lands.

After separating from their latest clash of blades the Overlord spoke in a deep voice that practically drowned the room with the power behind it.

"Give it up weakling. Your comrade's have already fallen to me and you are soon to join them in death. You all came here looking to 'save the world from my evil' yet now here you stand on death's doorstep just waiting for me to give the final push. Now usually I would enslave you to my will like I have done to the rest of those who dwell within my domain, but I feel death is a much more suiting punishment for your foolish actions." Stated the Overlord in an almost bored tone as he gestured to the bodies of the others that had come with this man in order to slay him that were dressed in similar armor and strewn about the throne room. The young knight's grip on his blade tightened as he grit his teeth and his eyes burned with utmost hatred at the Overlord.

"Damn you! My comrade's may have fallen but I will not! I will kill you here and now and become a legend! Afterwards I will break this pitiful realm stone by stone and exterminate these vermin you command and then I will take your mistresses as my personal whores until they become nothing more then toys that I will then toss to the masses to do with as they wish!" Declared the man and just then the room went dead silent.

The minions stopped their cheers and actually seemed to look scared. Kelda for her part looked furious at the mans words while Fey had a more disgusted look as if the man wasn't even worthy to look at her much less touch her. Juno had the most surprising reaction as she smiled deviously and laughed.

"Hahaha! Oh you really are a stupid one. Not only are you fashionably handicapped but mentally as well."

"And why is that harlot?" Asked the man in disgust all the while not noticing the eyes of the Overlord now burned bright with rage and were beginning to turn blood red.

"Because Sea-Boy is very protective of us, and those things you just said is like signing your own death warrant. Say hello to your friends for me when you see them will you?" Said Kelda mockingly.

Before the man could respond he found himself choking a foot off the ground as the Overlord had him by the neck in one hand while the other held his blade that glowed menacingly in the light the lava gave off.

"I was gonna make this quick and save time, but after what you just said you will experience absolute HELL BEFORE THE END!" Roared the Overlord as he began the mutilation of the man who threatened his mistresses.

A few minutes, and a lot of bloodcurdling screams, later and the so called 'hero' was now a bleeding mess on the throne room floor. His armor warped and shredded as his leg's were broken in multiple places with bone sticking out in some spots, his right arm was ripped from his shoulder and the wound cauterized with the Overlord's magic as his other arm was nothing more than a limp of flesh as the bones in said arm were basically powder now. Finally the man's face was a lump of strip's of flesh as his skull could be seen in someplace's as well as his one eyes seemed it was gouged out by a hot poker, or the Overlord's magic enhanced finger.

Standing over what was once a human being was the cause of his anguish in all of his evil glory, gazing down in contempt without an ounce of mercy. Gazing at the man a moment longer he suddenly reached down and lifted the man by the neck who could only groan in response to the agony he was feeling, his vocal cords had been abused with screaming to the point it would be a miracle if he ever spoke again, if he would live past the day it was.

Carrying the man over to one of the lava flows, before finally shoving his face into the molten rock and watching as he failed around, as much as he really could, while he was burned alive till the point he finally stopped moving.

With the task done the Overlord dropped the body and turned towards his audience.

"...well? What are you lot waiting for!? Clean up this mess and get back to work! And Gnarl, make sure my 'project' is going along as scheduled." Added the Overlord as the minions rushed to clean up the bodies of the heroes that had invaded the Netherworld and Gnarl hurried off to make sure his masters request was coming along as planned.

Sighing in slight exhaustion the large man walked over and plopped down on his throne with his blade propped up on the side. His mistresses quickly fell in with him with Kelda and Fey sitting on the arms of his throne as Juno plopped herself in his lap though he gave no reaction as this was the norm for them by this point.

"You seem stressed dear, care to release some of that tension?" Juno purred before Fey stepped in.

"Calm yourself harlot. You've already had your time with him. Plus I think he would prefer a Queen's touch more then that of used goods." Stated the Dark Queen with a smug smirk that had Juno send her a scowl.

"Enough. I told you girls I hate it when you bicker, plus we have a guest." Said the Master of the Tower as suddenly someone appeared in a small flash of flames.

The new arrival was clearly feminine and looked to be in her mid to late teens as she stood at most five foot five. Her skin had a sort of copper shine to it and her fiery red hair was mostly cover by her brown shawl that matched her simple brown robe that, while modest, did nothing to conceal her impressive figure. The most catching feature however was her her eyes, which burned like gentle flames at a campfire.

The Overlord stared at his new guest for a moment before waving his mistresses off, who left without a word of protest as they understood the seriousness in this situation. When they had finally left did the woman speak.

"It has been a while. I see you've done much for yourself during your time in this world." Began the woman trying to strike up a conversation. Too bad her host wasn't having any of it.

"Enough games, we both know why your here. Your here to try and appeal to my 'good nature' in hopes that I won't follow through with my well deserved revenge Hestia." Stated the Overlord to the now identified Greek Goddess of the Hearth. Said Goddess narrowed her eyes but the sadness could be seen in the burning orbs of her's.

"I know what they did was beyond horrible, but they are still your family Perseus." Stated Hestia softly and that only seemed to enrage the giant man even further as he suddenly stood from his throne and took off his helmet and revealing his face.

The man's face was handsome, what with his roguish features, lightly tanned skin, raven black windswept hair. Even the scar going over his right eye didn't detract from his appearance, one could say it actually enhanced it. This was the real man behind the Overlord, Perseus Jackson, Son of Poseidon, Twice Savior of Olympus and betrayed hero of the Gods.

"Being family doesn't negate what they did Hestia! After all of my sacrifice all I wanted was a life of peace but Zeus wouldn't let me have it! So many people betrayed me Hestia and in the end they tried to kill me for their actions! It was only through Chaos intervention that I was sent to this world instead of to Tartarus like Zeus originally planned. Now I have a chance to make him and everyone else who tuned against me pay and I'm taking it. I know you care for them Hestia but now they have crossed the line. I admire that you still love them after all the have done, including me, but they have gone to far and now must pay the consequences. I know you must be ashamed of what I have become but I've made my bed and I am more than willing to lie in it to whatever end. I can only pray that one day you can forgive me and understand that this needs to be done." Finished Percy as he turned and looked away from the hearth goddess.

Despite his words Hestia was one of the Goddesses of his world that he truly cared for, maybe even loved. But she was a maiden goddess so he never really tried with her. Still he could never truly bear to see her sad or dissapointed, especially when he happened to be the cause of it. So imagine his surprise when he felt her warm touch on his face as she gently lifted his head so he could see her giving him a sad, but hopeful smile.

"I am not here to stop you Perseus, no matter how much I love them I cannot defend their actions or deny that they deserve punishment. I only came to ask that you seek your revenge against those who truly deserve it. Despite everything you've done and are in this world I can still see the same demigod who I favored above all else. Even to the point that I had considered breaking my vow." She whispered the last part but nevertheless Perseus still heard it and pulled back in shock.

"Bu-... how? Why? I am not the same demigod I was before Hestia."

"I know that. You have done terrible things in this world but you still possess the same traits that made me fall for you to begin with. While you are cruel to your enemies you care for the ones you love and would never raise a hand against them. While you have killed hundreds you enslave thousands because you still value the lives of others. And despite all the odds you still have hope that you can accomplish anything you set your mind to. That is why I fell in love with you Perseus and now I am not afraid to admit it because of my oath. Our last conversation only solidified the fact."

Percy was truly stunned by her admission and was kicking himself for not realizing it and acting sooner. Maybe then he wouldn't have hooked up with that whore of an Athena spawn and wound up where he is now. It was even more surprising that despite everything he has done as the Overlord she still had feelings for him. He was only broken from his musings when he felt Hestia's other hand come up to grasp the other side of his face and pull it down to meet her's in a chaste kiss.

From an outside perspective it would love very awkward for a giant being bent so low just to kiss a much shorter woman. To Percy and Hestia though it was just perfect. For once the Son of Poseidon could not feel the anger that raged in his heart for the Olympian's that had betrayed him and just immersed himself in the gentle warmth that Hestia's lips offered.

After a few minutes of this they parted and Percy noticed the small pain in his back from being bent over for so long. Still he couldn't complain as that was the most amazing kiss he had ever received.

"So... what now?" Asked Percy as he wasn't sure where they went from here. He was still going to take revenge on the Olympian's but at least he had solice that Hestia, and maybe a few more, weren't really as against him as he had originally thought they would be.

"Well if I'm gonna be the mistress of the Overlord I think that a certain oath has to be gotten rid of don't you?" Said Hestia a bit playfully with a lustful undertone that surprised Percy as he never expected it from her. And that's not even counting what she said.

"Wait what? Your actually okay with my other... 'relationships'?" Asked Percy in disbelief. Having been around her siblings so long one would assume she would be highly against any multiple partner relationships.

"I have been around for a long time Perseus and your situation isn't exactly unique with some of the things I've seen. While I never pictured myself ever being in, or any romantic relationship, I would be willing to give it a try for you." Stated Hestia resolutely.

Percy paused for a moment to take in her words and Hestia was afraid she may have said something wrong. Those thoughts were banished when Percy suddenly scooped her up bridal style and started heading for his quarters with a surprised Hestia. Before she could protest Percy suddenly leaned down to whisper in her ear.

"If your gonna be my mistress then call me Percy when we're in private like the others."

"Of course... Percy." Sighed Hestia as she snuggled into the demigod's chest feeling happier then she could ever remember being. That didn't stop the dark thought from crossing her mind though before they reached Percy's chambers.

'Our family were fools for betraying you Percy and while I may not want them to suffer I will stand by you through it all... my Overlord."

Well there's the prologue chapter. Left some hints and while you may think that I just up and slapped Percy and Hestia together there will be flashbacks that say how their relationship built up to this point as this is a few years after Hero's of Olympus end's and later chapters will detail the event's pertaining to how Percy became the Overlord.

Review and/or PM me.