The Gremory Devil Enters Remnant

Prologue: Betrayal and New Beginning

*Narrator POV*

Do you believe in Angels, Devils, and Fallen Angels? What about dragons and magic? Well, they are all real, and they live among us in secret, but some secretly recruit us to join their ranks since most of their Pure-Blooded members have fallen during the Great War so many centuries ago, along with God and the Original Four Devil Kings. Now, you may be wondering, where is this story going?

Well, it begins years after the Great War, and with a certain Gremory Devil named (Y/N) Gremory, the Eldest Son of Sirzechs Lucifer and Grayfia Lucifuge and oldest brother to Mallicas Gremory. Now, (Y/N) was born around the same time as Rias Gremory did, so they're "twins" by birth month, but Sirzechs had (Y/N) away from Rias most of the time so he would be trained better and powerful than Rias, which was true to the fullest. (Y/N)'s mastery of the Gremory signature power, the Power of Destruction, and his mother's power to control Ice, but later on Sirzechs gave (Y/N) other spell grimoires with magic of Black Lightning, Hellfire, and Shadow magic. (Y/N) was a special case in the devil race as he can master magic quicker than other devils. (Y/N)'s power alone was stronger than most High-Rank Devils, and almost on par with Sirzechs himself. Sirzechs gave (Y/N) a special necklace that hid his magical power, which was good in the case other devils would try to kidnap (Y/N) for his magical power and use him for their own gains.

One day, (Y/N) wanted to get a feel what it was like to be in a peerage so that in one day, he would lead his own peerage. Sirzechs thought of the idea and was about to suggest being placed in his peerage, but (Y/N) wanted to be in Rias's peerage since his father was too busy as the Devil King. Sirzechs was against the idea at first but reconsidered when (Y/N) brought up the fact that he couldn't be around. Sirzechs hesitated but went with the plan and had (Y/N)'s last name changed so it wouldn't draw suspicion from Rias. Sirzechs introduced (Y/N) "Lucian" to Rias and had him placed as Rias's First Pawn. (Y/N) went with Rias and was further introduced to the ORC, Occult Research Club, and met with Kiba Yuuto, Rias's Knight, Koneko Toujou, Rias's Rook, and finally Akeno Himejima, Rias's Queen. Once all the introductions were in order, (Y/N) was later inducted into Kuoh Academy as a Third Year with Rias and Akeno and had the same class as the two.

Some time went by and later both Akeno and (Y/N) were happily dating, which had Rias in a jealous mood, most of the time, but learned to support them as well. Koneko was a little jealous but was happy for them. Kiba was happy his friend had some happiness in his life, but all good things sometimes have an ugly beginning. Which happened when Rias resurrects Issei Hyoudou, the major pervert of Kuoh Academy, and things have taken a different turn badly. Whenever Issei does something perverted and causes grief for the ORC, (Y/N) confronts Issei about it, but (Y/N) gets beaten and abused by Rias for hurting her "Favorite Piece." It was at the moment, (Y/N) found out that Issei, of all people, had the power of the Boosted Gear of the Thirteen Longinus, and Ddraig was a Heavenly Dragon. That wasn't all, the relationship between (Y/N) and Akeno was wearing thin when the two haven't been seeing eye-to-eye on any stable ground. This caused the two to keep apart for a while and not talking, but made up here and there, but it always led to the couple to continue the same role over and over again. There were times when (Y/N) used his magic to enter Issei's Sacred Gear and met with Ddraig himself. The two have gotten along better than his relationship with Issei, and Ddraig taught (Y/N) a bit of his Boosting Magic but could only use it for a short amount of time with limited boosts in power. Ddraig was impressed with the time it took for (Y/N) to learn his magic and found out (Y/N) was the Devil Prince of the Underworld but decided to keep his secret from Rias and the ORC.

More events later, Asia Argento, now Rias's Bishop, was added into the Peerage and considered (Y/N) as an older brother of sorts. Later on, came to the "arranged wedding" between Rias and Riser, but what most people didn't know, (Y/N) and Riser were good friends and Riser dropped his third-person speech around (Y/N), and (Y/N) got along with Riser's Peerage and they were friends, but some wanted to be more than friends.