Hmm...
She's technically had different names in all the games she's been in.
Sakuya
edit:
recapping my question:
- doesn't kill you on collision
- can return fire
- you must attack in order to advance
the answer is.. the tiles in HRtP. I'm replacing this question, because I haven't realized that the tiles aren't really a character.
New question (to replace the former):
- hasn't appeared so far as a selectable character or an opponent
- have appeared more than once in the games