Currently been going through the Arcade with everyone for the trophies. I have 6 left(Raiden's glitched out on me last night, so I couldn't fight the final enemy), so I haven't played as everyone yet. But from my adventures in arcade mode. Toro seems like he could be really good. His Mochi Hammer thing(Down Triangle, IIRC) isn't all that bad. Easily spammable, and can get a level 3 in less than a minute by just spamming it. I believe 4 or 5 hits for level 1, 6 for level 2 and 9 or 10 for Level 3.
Take me out, out of my life, sing to me a lullaby Cradle songs from a new life, don't forget to pass me by