Chandra, Fire Artisan
Oracle Text
Whenever one or more loyalty counters are removed from Chandra, Fire Artisan, she deals that much damage to target opponent or planeswalker.
+1: Exile the top card of your library. You may play it this turn.
-7: Exile the top seven cards of your library. You may play them this turn.
There's room for gaining loyalty abilities, as Nickey B shows.
The moment I saw this I thought "cool! now they have to take a punch to the face if they want to kill her.." but I am not sure how it works with her taking damage?