Here is the rewrite. Figured I might as well do this as I catch up with the novels. This time it features the actual Issei Hyodo from canon. This is inspired from 'Trials of the God Harem King' in Questionable Questioning, I recommend you have a look at that DxD/Exalted crossover.

Our two Isseis will be introduced so to minimise confusion 'Ise' is the pervert version and 'Issei' is the Super Devil version.

Story start Narrator POV

"Oh it's you again! Hentai featuring big oppai again huh? Well then that will be 2400 yen! Come again!"

Walking out of the store is Hyodo Issei, Kuoh academy freshman. It is a prestigious former all-girls school that recently went co-ed. Issei, ever since that old man told him about the wonders of a woman's chest when he was six years old he has become obsessed with it. Knowing about Kuoh's recent changes, Issei for the first time of many times to come put his libido to good use by using it as a motivation to study.

The result is him passing the entrance exam with flying colours. Hence it is a real shame that he decided to proclaim his dream of having a harem during his first day which alienated the girls. The fact that his two friends he made and the title of one of the Pervert Trio did not help matters at all. Soon they had a very bad habit of peeping at the Kendo Club girls while they change which results in many beatings and further alienation.

"Huhuhu! Oppai Island Tribe! I have been waiting for this!"

Back to our loveable pervert. He is taking his normal route home, minding his own business and looking forward to watching the hentai he just bought when he heard a voice in a nearby alley.

"Help…me…"

Issei froze on the spot and turned to where he heard that voice. He saw a bloodied man, who look like he was ganged up on and brutally beaten with many arrows sticking out of various areas of his body.

"Are you ok!?" Issei, being the kind soul he was, rushed over to tend to the injured man who gave a weak smile.

"Please…pull the…arrows out…" The man rasped out in agony. Issei looked at the arrows and hesitated, all of them were stuck very deep into his flesh.

"Are you sure? They look like they are plunged deep into you." Still wanting to help Issei asked.

"I'll…be fine…" The man rasped out again.

With shaking hands Issei grabbed one of the arrows and pulled.

"Gaaah!"

"Ah! I'm sorry!" Issei cried out thinking that he hurt an already injured man.

"It's ok, please do the same for the rest." The man reassured him.

Then came more groaning and wailing as Issei painstakingly pulled the rest of the arrows out of the man's flesh. The exhausted man then lay on the floor, blood pouring out of the wounds. Issei was about to call for help but he interrupted him.

"Boy…please…give me your hand…" The man pleaded with a weak smile.

Issei complied, crying at his perceived failure of saving a life decided to be with this stranger at his last moments.

"I'm so sorry…" Issei wept as he held the man's hand.

"No worries…We will meet again." The man smiled. Then before Issei's eyes, a green glow enveloped Issei's hand to his confusion. To his further confusion, he watched the man's body dissolve into dust before being blown away by the wind. Even the blood on his clothes vanished.

"Well that was weird." Issei mused as he went home, oblivious that his life will soon change.

Scene break Ise POV

After meeting with that injured guy that somehow disappeared, I went on home. I am currently having dinner with me parents.

"Ise bought another hentai anime."

PFFFFFT!

What the hell was that!? How did mom know that!? I made sure to hide it! But then dad spoke.

"More of it huh? I suppose our family line ends here…"

Dad said in despair. While I am not even 5 feet from him.

Dammit! I am STILL a healthy 15 year old! Please have some more faith in me!

"Oh just you wait dad! I will bring some of the hottest chicks home and have sex with them all night!" I proclaimed angrily.

"This is officially the 12th time you said that. But still, good luck with it."

Oh shut up! What really matters is that I back up what I proclaim! No matter how many times I proclaim it!

With that, our discussion for dinner turned to other subjects.

After dinner I retired to my room, where I watch the hentai I bought today. And boy is it worth every yen spent! Big oppai everywhere! KGGGGHHH! If only this island was real and I was in it! But then I also know that is just my own fantasy, I still want to grab and suck oppai for real!

After dumping the used tissues and taking a bath, I got ready for bed. Today is a Friday so I have two more days to enjoy that hentai with my two pals!

'Is it now?'

Wha-what was that!? That voice…It is the same voice from that man I met earlier!

'That is because I am that injured man from earlier.'

Wait…you can read my thoughts!?

'Yes I can, I sealed myself inside your soul when you gave me your hand. It preserved my existence, thank you.'

You are welcome? That does not explain anything though. Like that weird light that covered my hand or your body turning into dust so quickly.

'Oh, my body turned into dust? I suppose I cannot hide it from you now. I will tell you but first you need to be where I am.'

Ok cool. Except I do not know where you are.

'I have said before. I am sealed within your very soul-'

That does not explain anything! HOW do I enter my soul to see you!?

'I was about to say that. Little boy. Anyway before you can interrupt me further, I will tell you how to see me. First prepare yourself for bed.'

"…"

'I'm serious. Take a bath, brush your teeth, wash your face and other things. Do it.'

I already did all those.

'Oh okay then. Now lay on the bed, close your eyes, relax and imagine that you are in a completely white area.'

If you say so, ok so lie on my bed, close my eyes and imagine myself in a white area.

SHINE!

Whoa! It really worked! Ok so I am in a white void just as the voice said. Seriously, all I see in front of me is white, the ground I am stepping on is also white expect that there are ripples similar to water ripples, though it is not water since my feet are still dry.

"Well done boy."

I turn around behind me, where the voice was and…Am I looking at myself? In front of me is someone who looks exactly like me! Well there are exceptions like he is about a full head taller than me and more muscular but other than that his face is a lot like mine. If we were side by side people will think that he is my big brother!

"Well this is interesting, you look like a younger version of me. But we have no blood relation at all." The man said, knowing my thoughts.

"Oh okay. My name is Hyodo Issei. Pleased to meet you." I introduced myself

"Wow, this kind of coincidence is odd. My name is also Issei. But my name is Issei Beelzebub." He replied, I was a bit surprised that he is also called Issei, but then there are many people called 'Issei' so I am not too surprised.

Wait…Beelzebub? As in the Beelzebub recorded in the Bible?

"You seem to be aware of my last name." The man said to me.

"Yeah. I read the Bible with my childhood friend once. Beelzebub is a 'Prince of Demons'." I said.

"I see. I actually am a king of demons."

Wait…Devils actually exist?

"Your expression says that you did not believe the existence of the supernatural. Yes, they exist in this world. The myths are true. For example, the Shinto deities Tsukuyomi, Amaterasu and Susanoo actually exist."

"Eh? EEEEEEEEEEEEEEEEEEEEEEEEEEH!?" I shouted in disbelief. I know that my parents do pray in the shrines of Amaterasu. But I never thought they are real.

"Well then, do you want me to tell you about our history?"

"Uhhh…Yes?"

"Ok then this will be a long lecture."

Scene break Issei POV

"So…All the myths are real, there is a massive war fought between the Angels, Fallen Angels and Devils which lead to near extinction of all three sides. You, a Maou formed the current devil society by starting a civil war with those who still want to continue the war which your side won. But then you travelled the world and fought off the gods for centuries?" This boy summarised.

"In a nutshell this is correct." I replied.

His stunned expression is quite amusing, staring at me as if I grew a second head before his eyes.

"This is very difficult to take in…" The boy said after a few seconds.

"Then let's change the subject. For preserving my existence, I would like to reward you, what would you want?" I ask the boy, while my physical body died, my soul is in this boy and if he were to ignore me, I would have been reduced to nothing in the literal sense of the words.

"Oppai."

Wait what?

"Sorry, could you say that again?" I asked, incredulous.

"I want to grab and suck oppai! These two globes that define the beauty of a woman! That nourishes the mouths of babies and infants! That bounces so seductively in the dreams of men! I also want a harem full of hot girls that I can have sex with all day! ALL HAIL OPPAIIIIII!"

Well, I was not expecting that. I was expecting more of wealth since I have vast amounts of it, or even power since I can provide it. But to enjoy a woman's breasts and have a harem? I suppose I truly cannot judge a book by the cover. This boy can take the title of Asmodeus if he were to be a Maou. But this raises a question about his morality, with how he loves breasts what of the woman?

Ok. Let's try this then.

"If that is what you want. I can give you some of my power." I said, getting his attention once more.

"Huh? Why?" He replied with a question.

"You can use my power to drag some well endowed girls to somewhere quiet and enjoy their breasts and the rest of them by force and then keep them in a secluded area so that you can enjoy them later. Then your dream will be met right? You can also use my power to fight off the authorities as well." I said this statement, not as instructions, but to judge his character. Is he a vile person with a kind façade or is he a kind person with good morals?

"Wha-WHAT!? Hell no! The girl will be hurt! I don't want to achieve my dream like that! The girl will cry! I only want girls to let me grab their oppai by their own free will! That is rape and is absolutely disgusting!" He replied angrily. Looks like he is the latter.

"Very good. That is what I want to hear. My apologies, my proposal is to judge your character and I have to say you passed this morality test." I said to him.

"Oh, I see."

"However, do remember that there is more to a girl than her breasts. Love a girl for being her and not just having a bountiful chest. Then she will love you back."

"No, worries! I want a harem because I love girls as girls and-wait. How did you know that?" He asked me.

"I have many lovers in the past."

"You had a…harem?"

"Yes, I-"

"Damn you! People like you stops me from getting girls!" He then went on a tirade on how people like me will seduce all the girls and leave none for people like him. It is actually amusing so I let him rant until he tires himself.

Ise POV

I ranted on how this guy makes me unable to have a girlfriend. He is like that damn pretty boy Yuuto Kiba! All the girls love him just because he has good looks! Grrr! It pisses me off just thinking about him! But then, am I really justified in ranting it to this guy? He may have a harem, but when I met him he is near death, he also said that he had been fighting for most of his life.

"Are you done?" He asked once I calmed down.

"Yes, sorry for venting out all my frustrations at you." I replied.

"Back to what I was saying. I have many lovers due to the amount of power I have. In the supernatural world, power attracts power. It also attracts the opposite sex to you."

Well THAT got my full attention.

"Also there are many attractive females in the supernatural realm and if you have enough power, they will come to you. So do you want power?"

"Oh hell yes I want that if I can get a harem!" I replied happily.

"However, I cannot just give you all my power. Your body is too weak to handle it, if I give you too much your body will break down and you will die. It is like a balloon bursting due to excessive air in it." He explained, so how much power he can give me is based on how strong I am.

"Hence I will train you, make your body stronger so that you can handle my power. There is also another reason, now that you had an encounter with the supernatural. You will have more encounters of the supernatural. Some of them may even be hostile towards you and you need to be able to fight them off."

EEEEEEH!? There will be people who want me dead!? WHY!? I just want to get some girlsssssss!

"It is unfortunate, but that is the way it works. But, I will help you in defending yourself. So do you want to train so that you can get some girls and protect yourself?"

Well, if what he said is true, then I have no choice. Might as well make the most of it and get my harem.

"I want to train." I replied to him.

"Are you sure? The training will be very harsh and I will not be surprised if you were to resent me.

I gulp. Looks like I will be going through hell. But then something popped up in my head.

"Wait, how do you train me if you do not have a body?" I asked him since this is his soul and his physical body turned to dust.

"You have a point, but you are also in your soul form. Your abilities in your soul form will be the same for your physical body. For example, if you can do 1000 push ups in one go here after some training with me, you can also do 1000 push ups in one go with your physical body even if you did not exercise at all."

Wooooooah! That sounds too good to be true.

"Sounds too good to be true? I will let you find out yourself. Are you ready for training?"

"Hell yes I am!"

"Good, now first thing you need is endurance, you WILL get hit in a fight so your pain tolerance is top priority. Now raise your fists."

I complied.

"Now try to block my attacks."

Wait block your att-

WHAM! WHAM! WHAM! WHAM! WHAM! WHAM! WHAM! WHAM! WHAM!

"Start blocking!"

I barely managed to whimper out in pain from my right leg in my stomach, my arm in my brain and OH GOD IT HUUUUUUURTS!

Then he looks like he realised something.

"Oh of course! My first students were also devils, I forgot that humans have a weaker body so I did not hold back as much as I should have. Sorry!"

You know what? About the whole resenting you part. YOU ARE SO RIGHT! I HATE YOU SO MUCH!

Aaaaand done!

So the idea is that Ise met the other Issei a year prior to canon events and things start from there. So there will be some changes in Issei Beelzebub's bio in chapter 6 of my original fic.

No vessel is created and Ise did not die.

Issei was attacked by the Old Maou faction a year before canon instead of 2 years.

Ise's harem will be the same in canon and one more which will be revealed later in the story, he will also have the same skill set in canon since Boosted Gear went to him after Issei died but with some extra skills which will also be revealed later in the story.

My OC version of Issei will stay inside Ise as a mentor within so as to not hog the scenes too much. And I will say it now, Ise will be in Rias' peerage. One he is still human even with Issei Beelzebub sealed inside him so he needs to be a devil in order to live as long as his harem members and two, I also want to write their reactions to Ise's clients.