Riku from kingdom hearts.
He is a very popular character in the kingdom hearts world and even in the newest game his story line actually surpases Sora's. I would love to see Riku as a DLC character more than Sora and who know maybe he would be easier to get from Disney. Just a thought, and also in the new game, something very surprising happens that i was pretty shocked when i read it.
I was shocked at the end to 3D as well. but I think sora would get in if there would be a KH rep.
Do you have moveset of Riku? Plus Kingdom Heart characters such as Sora and Riku were owned by Square Enix with some Americanize Disney characters which Square Enix have a rights to use Disney characters.