Merry Christmas and Happy New Year everyone!

This oneshot idea would not leave me alone! I swear it has been haunting me since I first thought of it, pressuring me into finally writing it. Well, are you happy now!

Don't tell me you guys haven't thought of it either!

Feel free to use this as inspiration for your works.

This idea was partially inspired by "Belphegor Lord of Sloth" with concepts taken from "Lesbian Vampire Killers", worst movie I ever watched on a plane. Seriously, I do not recommend it.

I do not own High School DxD.

Rias could not believe what was happening in front of her. Issei was facing off against Riser in a rematch. Despite her pleas to stop neither would listen, one out of pure spite and the other out of stubbornness to, as he so crudely put it, "let someone else take her virginity". She tried to get her brother to stop the match, but Sirzechs Lucifer denied her pleas with a smile on his face. Now, she could only watch as what would probably be a public beat down of her precious Issei.

On the battle field, Riser had already began the traditional taunting phase where opponents insult each other or say other things to get the other riled up. However, to Riser's chagrin, Issei was not playing along. Instead, he was mumbling to himself. Having had enough of Issei's disrespect, Riser decided to try to end it now. Conjuring up a ball of fire, the blonde devil launched it towards his opponent, shocking some of the audience at such an unsportsmanlike act. Others just thought that being a noble meant you could do whatever the fuck you want. Just when Rias was about to call out a warning to Issei, a silver object, moving too fast for even the eyes of devils, whizzed through the air slamming the attack into the ground kicking up dust and smoke.

"Awesome it's here!" Issei exclaimed as he ran towards the crash site. What that object was, it was obvious that he had been waiting for it. Perhaps it was a weapon of some sort that he was planning to use. But where did it come from.? When the smoke cleared, everyone was shocked at what they saw. A sword that had only been seen in the museum, wielded by the original Asmodeus during the Great War, the one and only Dylldo. Oh, and Issei was holding it in his left hand with the Boosted Gear active, though he didn't look too happy about it.

"How is this possible!" Riser screamed. "How could a lowly reincarnated devil like you summon Dylldo, the legendary heirloom of the original Asmodeus?!" That was the question on the mind of every specator, even Sirzechs. Which is why they were confused when Issei's responsed with a slap to his forehead.

"Seriously!" he said aloud, as if speaking to himself. "Not only does the hilt of the sword look like a freaking penis, you named it Dildo?! Of all things, Dildo?! Did you use this sword for battle or sex parties!" Everyone was baffled at what Issei was saying. Who the hell was he talking to, and how dare he call a legendary weapon a tool for orgies? That's when they saw a shadowy figure materialize next to Issei.

"Let's just say a bit of both." the shadowy figure responded with a chuckle. Then it seemed to notice that it had a semblance of a physical body. "Well whaddya know! Looks like the air of Hell is helping me gain a physical form, not that I'll be able to do much with it, I'm still dead as a doornail, trademarked to Charles Dickens."

"That's not the problem! I ask for your help and you give me a freaking sex toy! What kind of ancestor are you!"

"The one responsible for you and your parents' high levels of perversion."

"It was a rhetorical question!"

"Enough!" Riser interjected. "I don't know what trickery your pulling here, but there is no way that's the real sword of Dylldo…"

"Stop calling it Dildo!" Issei yelled at his opponent, interrupting his lines, with tears in his eyes. "It's bad enough holding this damn thing, but to know that people will talk about how I defeated you with a Dildo…it's so damn embarrassing!" Many spectators could not believe this was the same boy who earlier claimed the right to Rias's virginity.

"You think that's bad?" the shadowy figure said while laughing. "Imagine using a shield called Himen."

"Damn you you fucking geezer!"

"Quit ignoring me!" Riser yelled charging at Issei. That was when the Boosted Gear yelled, Transfer!

Turns out, the Boosted Gear had been active since Issei went to grab the sword. Since then 2 full minutes had passed before Riser charged at Issei. This meant 12 boosts, meaning multipling the base power by 256. And this power boost was used on a legendary sword. So when Issei sliced through Riser's charging form the attack was super effective and seemed to ignore the legendary healing ability of the Phenex and gave the man a deep cut that nearly bisected him vertically.

"It was at that moment that Riser realized he fucked up, all because he underestimated the power of Issei's Dildo." The shadow said as if he was a narrator while Riser lay on the ground bleeding to death.

"Shut the hell up old man!"

Everyone was too shocked by what happened. A lowly reincarnated devil challenged a member of the illustrious Phenex family, and defeated him with a revered treasure belonging to the original Asmodeus given to him by a mysterious figure who was apparently the boys ancestor. What the fuck was going on?! Not even Sirzechs knew, and he was the one who set things up for Issei.

After finally getting Riser medical help, Issei now stood in front of the devils, all of them dressed for the original engagement party while he was in his school uniform with the mysterious shadow floating around him as he held the sword of Dylldo.

"I must say Issei-kun." Sirzechs began as he walked up to the victor. "No one was expecting things to play out like they did, not even I. Tell us, how did you do it and who is this ancestor of yours."

"Well…" Issei rubbed his head as he tried to think of an answer while everyone stared at him waiting to hear it.

"Allow me Issei." spoke the shadow before turning to Sirzechs. "I am Issei's super great great grandfather." There was a loud collective gasp from everyone. "On both his mother's and father's side." There was an even louder gasp. "And I'm the former demon lord Asmodeus." This time the gasp was so loud it could be heard from Earth and a few people, men and women alike, fainted. "Pleasure to you meet the new Lucifer and I must say you've done a pretty good job of running the Underworld, aside from the fact that you haven't abolished arranged marriages between noble families. I mean come on! What the hell made you think that was a good idea?! Ignoring the fact that the chances of giving birth through such marriages are less than 0.01%, it's inbreeding! Nothing ever good comes from inbreeding! I should know I'm the original sin of lust!" As the supposed original Asmodeus denounced marraiges between pureblooded devils in front of pureblooded devils, everyone's mouths were hitting the floor.

"Hey old man." Issei finally spoke up, putting the sword against a wall, he did not want to hold that thing any longer. "How about you explain how you're my descendent and how you ended up like this?"

"Huh." Asmodeus said as he took stock of the state of his audience. "I suppose that's a good place to start." With that he told the tale.

Apparently, the history books of devils failed to mention the powers of the original demon lords with respect to the sins they represented. As the Sin of Lust, Asmodeus was not only skilled in many forms of seduction, but he could use it on any species be they Fallen Angel, Yokai, Elf, or Human. Part of this skill was his ability to change his body to any specification, even change his species down to the last strand of DNA, including his own sperm. Therefore, any woman he impregnated would not have a half devil child, but a full human or full Yokai. Of course, that does not change the fact that he is the father of said child.

Now, long ago before the Great War, Asmodeus had fun in Japan. A lot of fun. The end result were two children born from two completely different women. These children would grow and raise their own families. Generations later, the descendents of these two would meet and marry. These were Issei's parents. So technically, Issei's descended from Asmodeus on both sides of the family.

Now, when Asmodeus died in battle, his soul went to purgatory, the resting place for all supernatural creatures. As his soul lazed about, one day, he sensed a new soul entering purgatory. Interested, he went to check it out and met Issei who was dying from Raynare's spear. While Issei was human when he died, by possessing the Boosted Gear, his soul was bound to that of Ddraig thus he was heading for purgatory. As Asmodeus's soul examined his descendent, Rias used her devil pieces to reincarnate Issei pulling his soul out of Purgatory. However, he brought back with him a piece of Asmodeus.

"And that's the whole story." By the time he had finished, Asmodeus was looking less like a shadow and more like a humanoid figure, though he still lacked a proper face.

"I…see…" Sirzechs said slowly processing everything he just heard. He wasn't the only one. Rias, though, was mainly glad that Issei was all right and that he managed to pull through for her, a heroic act that made her heart go "doki doki".

"Never mind that!" Asmodeus exclaimed. Clapping Rias and Issei on their shoulders, "Hurry up and get these two married so they can bang already!"

"What!" the two teens spluttered, bewildered by what former demon lord was saying.

"What?" he responded with a confused look. "Issei's got a good pedigree and he's already claimed your virginity. The two of you are practically engaged already. Besides, the sooner he gets laid the sooner his true potential can bloom." That last sentence got question marks coming out of everyones head. "Oh come on! You should at least know that any descendent of mine is mediocre, and in some cases below average mentally, until they have had sex! And the more partners they have sex with, the more powerful they get. Seriously, what the hell have my devil descendents been doing if you guys don't know this basic crap!" Many of the devils in the room were thinking about the Civil War when he asked that question. As for Issei…

"Wait…so you're saying that fulfilling my dream of becoming a harem king will actually make me stronger?"

"Well…" Asmodeus replies with a grin. "It will certainly make you stronger, but you've got a ways to go if you think you can beat the creator of harems."

"Oh it is on old man!"

"Challenge accepted."

There is absolutely nothing mentioned about the powers of the original demon lords in cannon. And besides, the focus of this was not Issei vs Riser, but rather the revelation that Issei is descended from Asmodeus and and Asmodeus himself is hanging around Issei.

That's it for now. Please Favorite, Follow, and Review. But most of all, thank you for reading!