This is slightly different, as I didn't redesign actual existing characters. In this post I designed possible characters for an existing universe, namely Naruto. The idea is to create something different yet remain close enough to the original material that you could see these characters in the series.
So the first one is a clone made from the right hand of Kakuzu. The monkey boy is the son of Yamato, an anbu black ops that summons monkeys and uses a boken and mokuton as weapons. I designed him with feet gloves because he would use kunai with his toes too, a real monkey. The other two are sound village clan ninjas, i designed the cursed seal so it relates to the many fingered hand/wings of Sasuke but chose to make noses as jet-packs. The middle one is my vision of Kidomaru as an anbu for the sound.
These were done for a RPG that i created to play with my nephews.