(He’s from the game Super Paper Mario)

Dimentio initially appears to be a lighthearted villain, but also shows a psychopathic side.Dimentio is intelligent and a skilled actor and trickster, being able to fool all of his peers into believing his loyalty is true.  

He is also very arrogant, never believing there was even a chance of him failing to get his hands on the Chaos Heart.

(I was thinking his voice sorta sounds like Stelyos from Man On The Internet’s Dimentio Charming Magician. Something sorta like that. So you can go off that, that’s just what I’m personally going for.