Hi very cool model, especially the more recents ones with the clothing. Nice how u modeled the hair.

A few suggestion though:
The topology is not ideal imo, it doesn't have enough edge loops at the areas where he will deform the most. And a lot of triangles. But I'm not sure because I don't have experience doing low poly models.

But I guess this is a low poly game model? Will you be animating this?

About the character himself: very well executed, looks a lot like him, but I think you could make him look more evil. I don't know if ur going to stick to the original Akuma design, otherwise you could make his trapezuis larger (going higher) to give him a stronger impression.