Naruto is part of the Phenex clan and is the same age as Rias. The contract was made to have Naruto and Rias be married. However, there is a problem with Naruto. He has trouble with learning fire magic, so he is look down on by his family and is picked on by Riser. He is not respected by his clan for not able to use fire magic. The only people that talk to him and look down on him are the girls from Riser peerage because Naruto has always been nice to them. Riser's peerages that they were Naruto's peerage because to Riser they are just worthless girls and sex slaves, including his little sister Ravel. So, the contract was change to Rias marrying Riser and both Naruto and Rias aren't happy about that because Naruto has spent a lot of time with Rias and doesn't like the fact that she is now marrying his brother instead of him. Naruto liked Rias a lot to consider her is best friend, and they both didn't like the contract between them getting married to each other by force, but decided to go along with it because it was better then Rias marrying someone that didn't her as Rias, but a part of the Gremory family. Riser keeps picking on Naruto, but it ends up being a fight between them and Naruto is badly hurt. Naruto is considered high-class devil because he a Phenex child, and is good with close combat. Lady and Lord are tired of Naruto disgracing them and exile him. Naruto is shocked that his own parents gave up on him and to make matters worse they take away his evil pieces so he couldn't gain a peerage. Naruto makes a decision to get stronger, so he takes his peerage chess set and goes to attain his own peerage and become stronger. When he is away (mind you he is gone for about 4 years) and trains he comes across a spirit of a phoenix who ask why he is here what he is doing. When Naruto explains what's going on the phoenix trains him and Naruto obtains golden flames for his fire magic, black flames from learning senjustu which turns his hair Black when using the black senjutsu fire. The 4 years have passed and Naruto is stronger that ever and has a whisker marks on his face to show that he has an alliance with the kitsunes that he met over his travels. Plus, the spirit of the Phoenix that trained Naruto sealed itself into Naruto watch Naruto grow up and be there for Naruto as a guardian. Also, with the spirit of the Phoenix seal inside of him Naruto can borrow the Phoenix's power that it processes and use white fire with Naruto's hair turning white. After, hearing about the wedding between Riser and Rias from Rias' brother who finds Naruto and asks to save Rias. Naruto agrees to come back and crashes the wedding and challenges Riser and his peerage to a unofficial rating game for Rias' freedom, be a part of the Phenex Clan once again, and to take Riser's peerage away from him and make it his own.
Naruto/maybe Rias/Riser's Peerage