You should read a bit more, he is still like a demon but he is too weak to do much at first but later on he does in fact inflict eternal suffering on others and those who wronged him, generally going from him simply erasing their existence from the universe with no way to come back to constantly draining his enemies of of all their blood and then regenerating it in a endless cycle to gain more power.

Great read, mc has a great scheming mind (which makes sense considering he is very old) and his main goal is getting more power through various methods as he went from struggling to take down bandits to being able to crush suns with his bare hands as far as I have read (chapter 700), there is also a great plot (though it isn't explained for a while since the mc at the start had nowhere near enough power to start it)