No, Magus isn't a playable character in CC. Janus might be one of the characters. It's rumored that Guile is the alternate reality version of Janus (Guile being the lighter side and Magus being the darker side) but there is no proof of it. When I say "Magus" I mean the dark wizard from CT.

And no, none of the games on my list are Enix games. The only games of theirs that I played extensively were Actraiser 1 and 2, The 7th Saga and Illusion of Gaia. There was nothing I liked or disliked more about those games than the games I have listed, so I didn't include them.