Rise of the Overpowered in Apocalypse

A young man who struggle in his entire life to become a weapon however for some unforseen circumstances the man was able to scape from that struggle and lived a peaceful life.

however after years of peace everything turn up side down for the worst magic, spiritual power and other stuff emerge followed by monster, humans and some mystical and powerful races fight for their Survival.

how can the man made devil able to survive the ruin world facing treats to become stronger.