Fukushuu o Koinegau Saikyou Yuusha wa, Yami no Chikara de Senmetsu Musou Suru - Vol. 11 Ch. 77

[.b_shit]

Raoul was super godly powerful from the beginning, but the gods had sealed the dark side of his power until the goddess of love unsealed it after his first death

this is the real reason, u can read the early chapter...