[quote=@Rilla]
I just prefer not to use them often. Kei'taro being the exception, and DG, so far. But never in a situation where, I'm just about dead, then I use my transformation/ultrapowerfulmove to make a miraculous comback , ala [@Fallenreaper]'s mention of Anime.
[/quote]

I've seen it done tastefully once. My only issue with upping levels (transforming) is that you seem to eliminate your limitations rather than either add/alter/etc new ones into the mix sadly. 

For example what I did with mine, Iron's Werecoyote form uses magic yet at the price of being unable to use his primary weapons due to his paws being too large to hold them properly. He also lacks knowledge of anything other weapons useage so using another is out of the question. And his two spells, Illusions and Inanimation is limited and unless the latter is attached to a weapon, it's lethal status ranges on the item itself. Still haven't figured out his feather magic yet, however those are easily dealt with and likely need recharging with x amount posts/rounds/time/before being able to used again or require time to actually active which allow my partner to interrupt it. 

So it's possible to check and balance a transforming PC, but it has more to do with altering the weaknesses fairly. Though I will admit, the notion I have to start again from scratch to put a PC down when my PC isn't healed is not endearing in the least.