From Rias's childhood sweetheart to a Godslayer

Lin Luo traveled through the world of anime and became Rias's childhood sweetheart.
He even changed his job to become an original magician, and he will become stronger as long as he has knowledge.
He even made a contract with a demon from another world, extended his claws into the heavens and all worlds, and recruited demon followers.
......
Rias: Only Lin Luo is my fiancé.
Kasumigaoka Utaha: Master, I want to replenish my magic again.
Asia: As long as I can help Brother Lin Luo, anything is fine.
Akagome: Master, do you want to eat meat?
......
Before he knew it, Lin Luo was already able to kill gods.