Now. Before people start hating on me for doing something pretty cliche. I am going to do this differently. There are three categories for this list.
Human, Nonhuman, and Godlike.
Basically, those are the three you have to work with. You know... so we just don't place Demonbane as number one automatically just because of how cheap a giant over ten universe size time traveling Cthulu mech really is. So yeah, I am going to ban it from this.
But, by human powerful. I mean just a regular human being, they can have powers but they have to have been human born first and remain human. Like a superhero, but not Superman. Nonhuman characters are ones like Goku who aren't human but are in a class of power thanks to being an alien/have become an alien thanks to powers. Godlike ones are like Asura from Asura's Wrath or even a character like Kratos. They are born from Gods or are Gods or beings/things with Godlike abilities like Gurren Lagann.
So here is my list of these three categories.
Godlike character of my choice has to be...
Asura, from Asura's Wrath!
He is completely unstoppable and it is very likely he could also take on Gurren Lagann and win. He is that damn strong. It is almost unfair to put him up against anyone in any piece of fiction. We all know that this guy would win. If you are wondering why. Watch a playthrough or play this guys game. It is insane on how insane it gets.
For the Nonhuman section. It has to be the one and only.
The Demifiend! AKA Hitoshura.
This kid is insanely strong to the point where I fear that in any Atlus video game that I may have to face him again... In Digital Devil Saga, if you were to fight him in the optional boss fight. You better pray to whoever you believe in just for how much ass this guy is going to wipe the floor with you. The normal time to beat him is 2 to 4 hours. 1 hour if you have insanely grind-ed. No, I am not joking. Oh, and did I forget to mention that the normal battle theme from this guys game plays while he uses low level spells and demons only on you? Yeah... he considers the powerful characters in DDS as nothing but mere insects. That is freaking frightening. Now sure, Goku is a obvious contender. I just wanted to do something different here.
For the Human character, it has to be the one and only...
SKITTLES TOUCH MAN!
Wait... wut. Yes, you heard me. This guy is the most powerful regular human I have ever seen. This guy could quite possibly kill the above two guys and even Goku easily. All it takes is a single touch and this man has turned you into a pile of damn candy! This poor cursed man is basically Fist of the North Star but more kid friendly and instead of blowing people up with blood everywhere, he blows them up into a pile of Skittles... I can't tell which is more frightening. Seriously, this is the picture which helped me decide this choice.
Yeah... no one fucks with the Skittles Touch Man. NO ONE!
Who are your three choices for the most powerful characters in fiction?