Gwen said it best, but his animations and moveset actually do showcase a good amount of his personality and intelligence. From the obvious ones like his idle animations and victory screens, to the minor ones like the grimace he gives when he fails to grab someone with his Side-B or using his tail as a balance for his Up-Smash, they did a great job showcasing what the character is about and how smart he is in using the tools at his disposal. It's actually pretty impressive what they managed to sneak in for him.
As for voices, I always liked the suggestion of Robert Eugland for Ridley. He played
Scarecrow in Injustice 2 and I feel that would be a good direction for the character.