The sculpts are very nicely done.
But im very sorry to say that none of them did match in any wise with the guys.
Ursula looks like a very fat man. There is nothing female on her. Even if you could see the breasts, she would look more like a transvestite than an evil lady
You need to get more nto female studies. Women have another skull structure than men.
Lucky luke looks nothing like the guy. Its more a cosboy doing cosplay than a character from a cartoon stepping out from the tv.
Elmer Fudd looks more like the evil aggressive pink guy in dragonball than the tiny, gnomy, kind and stupid guy he is in the cartoons.
Akuma turned out quite well!
It’s hard to give cartoon characters a real life face. I had to face the same problem in some works as well, the only hint i can give you is to orientate on paintings and drawings and not on photo references who could match this character.
The most important thing is how you can bring the personal characteristics and the physical appearance on one rail. Catching these is the artistic part in it. When people are able to recognize the cartoon character without superficial hints like hats or other characteristical objects, then you got it right.