A guy I knew was able to do something with the skins. He was able to make a super Saiyan Goku npc for me by editing the Vegeta model,changing the hair color and I had to paste the link he gave me of the skin in the URL of a npc that was Vegeta and Bam super Saiyan Goku. Anyone know how he did it?
He re-textured the skin of vegeta (With his model), probably made it a URL and then when he was making the npc he pressed “Models” found the vegeta model and pasted the URL of the re-textured vegeta on the skins section. (If you click the first button after the top bar in the first section, it will change. I think it goes textures -> player -> URL or something.)
You just need to get the textures for whatever entity you want to modify from Jin’s mod by opening it in a zip program and find the assets folder. Then you need to edit it in something like paint.net (which is free) and then use it with the NPC like the people above said.