High School DXD (harem) x Grandson of Sparda (male reader)

Once at time, there are Legendary Dark knight name Sparda he is right hand of Mundus, known as the Prince of Darkness, is a devil prince who ruled the Demon World two thousand years ago, overthrowing the previous ruler of the Demon World and threatening the human world but Sparda have found truth love with angle name Eva then Sparda defeated Mundus, sealing him into a marble vault, and what was left of Mundus's armies retreated back into the demon world. In order to close the gateway, Sparda used his own blood, along with the blood of a human priestess (Lady's ancestor), in conjunction with his sword and a mystical amulet then they have hybrid twins sons name Dante and Vergil but Mundus free and kill Eva and back to demon world and Sparda was disappear and dead but in years later sons who grow up and meet Lady and Trish together to destroyed Mundus then years later Vergil had child name Nero know at demon Hunter but Dante fall love with stronger angle name Seraphim but they had child name y/n Sparda demon-angel hybrid known as a Nephilim, years later Y/N are teenager Mundus back to dead and stronger to destroyed Sparda family then Sparda family have no choice to give all power of Sparda and angle power and all demon and angel weapons to Y/N and sent to safe place in different world that where they have Devil, angel and fallen angels. And he met the god of this world and need his help but also he gives his new power before he sent him in the underworld.

And that when young rias meet young y/n in first time and become childhood friend (lover), also y/n was sent by portal one who uncle Vergil make portal for his nephew but he is last Sparda.