Tadaomi Karasuma x reader

Tadaomi Karasuma believed the world would've been a better place if he just accepted the idea of Koro-sensei's death... He wanted everything to become normal, being an agent, living in solitude and joy while being a normal teacher at Kunigigaoka Junior High.

Until he received a message indicating the world's once catastrophe had been brought back from the past through time travel to save the world....