Hmm, it's different and potentially interesting. I think it's one of those things I'd have to see in action to really get a feel for though.
It could certainly work as a special type of match at least, as you are planning for multiple game types and such though.
Though I feel transformation gimmick does kind of need a player sprite of some sort, as otherwise its all purely textual. Which could work I suppose, but I imagine a part of the appeal for TF is actually 'seeing' the process happen.