Ironically enough, this is what I imagined Ultimate GOop to look like ;
Also...I know yo weren't 100% into the idea...
BUT I do think I know why Kevin really joined with GWen and Ben. (remember, Ben didn't fully trust him at first during the early parts of AF and he STILL did illegal things, so he wasn't just 'Boom, I'm good' like most are thinking he was. (I sometimes wonder if people were watching the same show as I was ))
The thing about it that irks me the most is, would you ever want to be working with or even be near someone who tried to kill you when he was only 11 ? Another explanation could be that Servantis altered everyone's memories to downplay just how psychotic and dangerous Kevin used to be and that's why Ben is distrusting at first and not totally on edge like he should of been.
Another one I have is his species. Since he is a slime blob, he would be related to Gluto's. There are three different species, each which uses devices that help with their physical form.
I think sploot doesn't need that gravity disc. The device inside him is fine.
Maybe in Ben 10k He might be slightly bigger.
That sounds like a cool idea.
Improving this, since in the future timeline any remains of a villain are stored into Sector 15-D. One Student was helping a friend of his (who is a polymorph) recover from a strange disease, preventing him from shapeshifting and maintaining his physical appearance. When he takes a sample from one of Sector 15's Unstable DNA, the Polymorph winds up becoming Sploot.