Disclaimer: I own nothing that you may recognize.

AN: A few years ago I wrote the story Heir of Eden, which is still up for a while longer, and had some mixed reviews, and I lost my muse for the story. Now here I am writing a new High School DxD crossover.

AN2: In the past I have primarily used only dialogue and no paragraphs, so forgive me if they are poorly done

AN3: I realize that in cannon the Evil Pieces were not created until after the great war(which will be the next chapter), and brave saints came even later. In this story though they are being created much earlier.

Mini Update to explain things later on, just changed creation of systems back 3000 years, so I can have 2000 year old devils not be the most ancient

After spending 50 years recovering in their own realms the eight gathered back in Midgard and began to fill the dimension with planets, and stars, while each spending time on the actual planet which they collectively chose to call earth, on which they created a garden called Eden, which they placed the two keys in before giving them life. Shortly after giving them life, the eight noticed a plant that they had not planted in Eden, which would remove the immortality of whoever ate it but also gave them the power to create life, which would be the same as them. After discussing this new development the eight chose to permit the tree's existence but changed it so the keys would not be lost to the ground if the newly named Adam and Eve were to die, but that the keys would pass to the next generation of the race. In this same council Ophis pointed out that instead of the constant creation of new children of their own, perhaps Khan and the Four children of Satan could give the plant to their own children thus allowing them to grow their own forces faster, something which Red decided was a good point as well so gave a modified form to his creations in the Dimension of Midgard. Agreeing to the point which Ophis had made the Children of Satan had their children partake of a modified fruit which left them immortal but not invincibly, before taking of the fruit themselves. Seeing this Khan did the same, but due to his position of being an avatar of a dimension, it solely changed it so if he exerted as much energy as he had in binding Trihexa it would put him into a coma for 1,500 years instead of killing him.

1000 years after Midgard was finished, 6000 BC, Hell

"I see that you have come to me at last, my children, I had hoped that my sibling's loss was just an accident, not a purposeful attack, by our children, it seems I was sadly mistaken," Lucifer said sadly looking at the crowd of his creations that stood in front of his castle, one of whom came forward.

"Indeed you were, old man, I am Satan, called after the one who led our people against the hosts of the Angels of Khan for a millennium, before you and your three siblings overthrew him and weakened us, by giving part of our world to create a new one. But no longer, no longer shall the Devils sit idle and wait here in the realms of hell, but we shall go forth and conquer the world that was made in part of our realm before we conquer the rest of the realms, now are you with us or against us?" The one who came forward asked coldly.

"You know nothing of the true reason why the world was created, I will not fight with you, now be gone filth!" Lucifer said as he released a huge stream of energy creating a series of shields that surrounded his castle.

Knowing that he only had a short while before his wards would fall to this new enemy of his Lucifer quickly made the decision that perhaps the keys race would be of use in the war that he knew would come, so chose to appear to the Keys in the form of a serpent, and well the rest is history.

"Lucifer, what have you done?" Khan asked entering the garden of Eden as soon as the Adam ate of the fruit, which sent a ripple through the entirety of the cosmos.

"My children have made the decision to go to war against you and to take over Midgard as is their right, I chose to give the Keys of the fruit, to add another army to fight to defend this world from my children," Lucifer said sadly.

"What do you mean to defend this world from your children? I had thought we had ended the war between our races when you and your three remaining of Satan's firstborn aided me in locking away Trihexa," Khan said in confusion.

"So had I, but it appears that a group of younger devils have decided that it is owed them to rule three realms, I, however, do think that we have about six or so thousand years before they will have a force enough to defeat my own forces, but if you join along with my remaining loyal forces, we should be able to put down this rebellion when it reaches this realm," Lucifer said hopefully.

"So this world will again be the world for the wars, I hate this, but I suppose it would be for the best, I shall inform my own children and restart our training regimes," Khan said sadly.

"And I shall gather those loyal to me and cause them to continue training on their own, and in secret, we cannot afford this new rebellion to kill them all as they did to Leviathan, Beelzebub, Asmodeus," Lucifer said sadly.

"I see, I had wondered where the other three were, I am sorry for your loss, I shall reach out to my sisters and brother and see if they too could aide in this war, but I doubt they will, they have no love for either of our creations or realms, they will only step in if the realm as a whole is threatened," Khan said before leaving to return to heaven.

In the following millennia the forces of the Devil who called himself Satan continued to grow in the underworld, even dabbling in the art of creation as he created new types of devils including Succubi, Incubi, Sirens, Nekomata, Kitsune, Vampires, and Werewolves, the latter two rather quickly managed to escape the realm of hell and incorporate themselves in Midgard, increasing their numbers by using the very fast breeding humans, who were blessed with their expanded lifespan but left them sterile. Meanwhile, after a few hundred years some of the Angels came under the enchantments of the Succubi and Incubi who were working with Satan, so Khan was forced to cast them out, and thus creating yet another faction that may or may not fight against the forces of Satan, though with their desire to please Khan, it appeared as though they would fight against the forces of Satan.

While all of this was occurring in the already realized factions, the humans continued to grow in number, and in time they began to worship beings of their creation which managed to bring these beings into reality and giving them smaller realms broken off of Midgard. Upon discovering these new factions Khan, who had since begun to be known as the God of the Bible, went and visited with the leaders of the factions, and had them swear to join with him in the war to come. In time though these factions, along with Khan, Lucifer, and Ophis, who was mostly uncaring about the events, decided that in order to best protect them, the best course of action in aiding humans in the war to come would include gifting some with greater power, which Ophis and Chaos did with the faction leaders creating a new species of human, known as magi.

As the time that Lucifer had predicted came closer the forces of Satan grew more power-hungry and began to attack more and more often, and unbeknown to Lucifer and Khan, Satan had managed to convince a small sect of fallen to join his cause, and had also managed to locate one of the two keys, the other not being able to be found, and started making plans to free Trihexa.

Year 0, Midgard.

"At last we have all that is need to free our lord, Trihexa!" Satan said with a huge smile as he arrived in a room where a large gathering of other devils, fallen angels, and humans were standing, looking at one man.

"Yes, I am glad to be of assistance, Lord Satan," The man said calmly.

"Good, good, Herod, this shall be your crowning achievement and bring you down in history as the greatest king in history, everyone shall know you as Herod the Great!" Satan said before he started to chant.

"Khan, what is happening?" Chaos said appearing in heaven, for the first time since the binding of Trihexa, due to having felt a major disruption in the cosmos.

"Sister, I am not sure exactly, but I fear it may be that the threat I told you about millennia ago has managed to acquire a key to their side along with some of my angels, and are working to free Trihexa," Khan said before a large surge of energy broke through the realms.

"Oh it is good to be back, who are you fools?" Trihexa asked as he looked at those surrounding him.

"We are your masters, we freed you so you are owned by us," Herod said proudly.

"Is that so, I think not, I am Trihexa, not some pathetic thing that you could control, now I am going to go and return to building my army to kill my siblings at long last," Trihexa said with a grin.

"Oh, I like that idea, may we join you great Trihexa?" Satan asked coolly.

"Of course, but you shall be my pets and not my masters," Trihexa said before vanishing alongside all who had been gathered except one who had been hiding, who fled the space spreading the news far and wide.

Flashback

3000 BC Parthenon

"Khan, I take it that you received the news from the others that the angels who have left heaven and the forces of my son are trying to free Trihexa, " Lucifer said appearing at the Parthenon where Khan, his three oldest angels, and the leaders of the other newer realms.

"Indeed, however, I am not sure how we can handle this threat this time, I have not yet fully recovered from the last ritual to lock away my brother, and this time we do not have your siblings to aide in the binding," Khan said sadly.

"I am well aware, but neither do we have the forces to fight in this war as we did in the last one, the devils loyal to me make up less than half the number of those loyal to Satan," Lucifer said worry evident on his face.

"Now I understand that you two have been along, much longer than I have been, but have you ever given thought to allow your own kind to change mortals into your own, if they die, as a means of reward, as I have with the Valkyrie, Zeus has with the Heroes of Elysium, The Jade Emperor has done with the enlightened, and Osiris has done with his Grimm Reapers?" A man with short gray hair and only one eye, who had two ravens sitting on his shoulders asked after a few minutes deliberation.

"If I may add to Odin's point this group would be under the command of an actual member of your creation, though with time may be able to gain their own followers based on their actions, and would gain the same abilities as those of your creation," A blond-haired man wearing a toga said calmly.

"I have not heard of those things Zeus, Odin, Khan, I realize that our creations are stronger than the newer races of higher beings, but could we do something of the sort?" Lucifer asked in shock at the idea.

"Is that not what happens with our priests already, we give them power, and they aide us," Khan said still somewhat confused.

"In a manner of speaking, but they must die before they join and it is a blessing as they gain more power, and immortality," Zeus said simply.

"I think the idea has some merit, father, I just fear that if you were to do so it would be abused by the fallen or the devils, as they are more carnal based and tend to be more power-hungry so they would kill the entire world to gain more members of their organization," The angel to Khan's right said.

"Then set limits, perhaps base it on a game or something, I know that in the world that follows me a game with sixteen pieces is gaining popularity, and these sixteen pieces are broken into six types each with their own powers, the most important of which is called the Caesar, or King," Zeus said cautiously.

"I like Zeus' idea, but another option is basing off of a card game gaining traction among my followers which has a court and then the numbers one through ten, then the three pieces of the court," An man with a long thin beard, wearing jade armor said calmly.

"Lucifer what are your thoughts?" Khan asked after a few minutes of discussing with his children.

"I fear there may still be too much power, especially with the sacred gears that we created earlier, what if a faction gains one of the wielders of a sacred gear, do they hold the gear forever?" Lucifer asked carefully.

"If I may, this war will likely claim countless lives, so this will not be an issue, and with the obvious enmity between your people and the creations of Khan, I am sure there will constantly be strife between the factions, so I doubt that would be a major problem, but if you are so concerned then have fights among your own people from time to time to show their worth," A dark-skinned shaven man said in a bored tone.

"Osiris has a point Lucifer, so what do you think, I was personally feeling that the idea of it being based around the Jade Emperors card game sounds like the best option, as it would only be increasing the numbers by 12 for each member," Khan said simply.

"While I think the idea has merit I think there should still be more limits, at least for my own kind, because, as Michael said, they are more power-hungry. I think that they should only be given to direct family members of leading families, in addition, I think the numbers could be merged into one person to give them an extra power boost, and finally, we need to find a way to deal with the point of the Keys, what role will they play in this entire playbook?" Lucifer pointed out carefully.

"I think that Lucifer brings up all good points, brother, but I think that his kind should have the piece game as their base, as they are so much more outnumbered than your children, and will likely take a larger blow than your children will," Ophis said appearing out of seemingly nowhere.

"Ophis, I had not been expecting you, but I am grateful for your insight, Lucifer what are your thoughts on what Ophis has mentioned?" Khan asked carefully.

"I agree that my children will likely be hit the hardest, so I will agree to the terms especially if Zeus explains it better, later. Now what about the Key though, they should not able to be held as a servant of any faction, they were created to be mortals, perhaps magi, but still overall mortals, independent and balanced between the oldest factions," Lucifer said reminding Khan about why the two of them had initially created Adam and Eve, causing him to turn to his children and start talking with them quietly while the rest of the leaders looked on.

"What if, if a key is turned into a devil or angel they automatically made kings and given their own set, and simply become true crossbreeds of all the races they belong too," A blonde-haired woman at Khan's left said calmly.

"So a true member of both factions, but what about the loyalty that we had considered with the new angel or devil to their sire?" Lucifer asked carefully.

"I have an idea, pick me, pick me," Ophis said excitedly after a few minutes of deliberation.

"Yes, sister, what do you think would be the best option?" Khan said rolling his eyes.

"Well, why not make it so Keys can only find out they are Keys and the like after they have been promoted, and if that does not happen within a year, the key they hold fades away as if they died," Ophis said excitedly.

"What do you mean promoted exactly, you mean proving themselves worthy to be a King, I would think they would need more than a year to do that, at least normally?" Lucifer asked thoughtfully.

"If I may, Lord Lucifer, in the game that would be the base of your kind, half of the pieces are known as pawns and if they reach the opposite side of the board they can be promoted into any other piece aside from the King, so perhaps if the King determines an area is enemy territory and the key manages to get far enough into the territory they can be promoted," Zeus said cautiously.

"Then the key would only be able to be made into a pawn or a low number card, I assume, no matter what the King wants, I think that is agreeable, now one more point that was brought to me a few centuries ago, what if the key is a holder of a sacred gear or one of the swords that either I have blessed or you have blessed Khan?" Lucifer asked critically.

"I assume they could simply hold onto the powers, as long the sacred gear does not guarantee immortality, which we made sure is an impossibility, one more point though to make things safer for the key and to not cause a reaction, if a key is turned no one who is not of that faction will be able to tell they have been changed so there could, in theory, be an angel devil cross, but that could only occur if the key had already met the requirement to be promoted," Khan said as an angel flew into the room.

"My Lord, we were just attacked, by some horrifying beast, of which we have not seen since the war in which you bound Trihexa, I fear that Trihexa has been freed," The angel said shaking slightly.

"Damn, but we already knew this, I think Trihexa was just testing our strength, now to close this meeting I think we should perform a ritual to create these systems we talked about, and bind them to all of our realms so they cannot be altered, and bind them to the blood of Lucifer and my four senior children, Michael, Gabriel, Uriel, and Raphael," Khan said and after getting nods from the other leaders the five sat in the middle of a circle that was created before Khan started leading a chant, the other members of the combined council all joining their voices in the ritual in time.

End Flashback