I was unaware that it was a parody. What is it a parody of?
It's a parody of Shonen Battle Manga, stories where people have unique powers and stronger and stronger characters keep showing up like Dragon Ball Z, Bleach, and Yu-Yu Hakusho. It pokes fun at power-scaling, contrived/convenient plots, and the personas of archetypal heros villains and everything in between, but it does so in a way that is refreshing and it's so self-aware that it really has become a great story of it's own.
The main character's attitude and persona is completely humbled by his own strength and bored of the way the villains act and behave.
[video=youtube;zrfUJzfMZ_4]https://www.youtube.com/watch?v=zrfUJzfMZ_4[/video]