Lady Maria of the Astral Tower

Double Strike, Vigilance, Haste,Waltz. After triggering Waltz, loses it for this turn and gains: if she deals combat damage to a player, untap her and gain an extra combat phase (max once per turn). Whenever she loses life, put a +1/+1 counter on her. At the end of each combat, she heals 1 life and at the end of turn, remove a +1/+1 counter from her.

{r}: Deal X damage to any creature, where X is 1 plus her +1/+1 counters. Activate once per combat phase.