Next to me, little miss Medusa's going to look like a sweet, cuddly bunny!
Hades was the single best character to come out of Kid Icarus: Uprising, and he's generally agreed to be the only character people wouldn't have complained of bias about. Of course, his only role in Smash Bros is a trophy on the 3DS version.
He has to be experienced to be believed. So go and play Uprising right now. Here is a page of general quotes from the game (his name pops up over 200 times- that should tell you something).
He also has a ton of cool powers. He is also too big.
BUT HIS PALUTENA's GUIDANCE WOULD PROBABLY BE THE BEST THING EVER BECAUSE EVERYONE WOULD BE LIKE "WHAT THE FUUUUUUUUUUUUUUUK HOW ARE YOU HERE" AND HE'D BE AVOIDING THE QUESTION LIKE A TROLL BOSS
GEEZ SAKURAI IF YOU'RE GONNA BE A BIASED PRICK AT LEAST MAKE HADES PLAYABLE
- Unfortunately he does not appear until much later in the game
- Somehow, Pit explores his insides because of creepy fetish powers