One of Zblader's ideas got me onto this:
creature, perhaps called Troll
with lowish attack and highish HP
ability: charge: swap attack and HP for 1 turn.
things to decide
- should 'charging' make you need a turn to recover (i.e. 1 round of time bubble)?
- I'd like it to be dual elements, which two do people think best (as in for card and ability)?
- would this just be too OP with things like BB?