Guts is more like Batman then Goku. Gut's technically has no power. Just an insane amount of skill. Okay, an unrealistic amount of skill. But for his universe, he started out as an ordinary human.
You can pull out the "durr hurr, it's just shonen with blood, guts, and rape" all you want. It still features a seemingly normal protagonist going around killing gods and demons, and thus fit's the op's request.