(The book's real title: I, the High-Spec Wolverine) PS: High-Spec Deadpool would be pretty good too.
Serious version: An immortal monster, alone in the world, with only the bone claws in his hands and gods of every kind before him. The only meaning to his life is to fight.
For laughs:
"Second Bro, another out-of-control Heroic Spirit has appeared in City H. Go deal with it."
"Second Bro, those cultivators in City G are about to fight the mages!"
"Second Bro! Our Gundam has engaged the alien squad! Requesting orbital cannon support from the ground!"
"Xiao Er, the Land of Light is asking to join the alliance. What do you think?"
Wang Xiaoer: "Is something wrong with this world?"