Scourge of the Throne

Flying
Dethrone (Whenever this creature attacks the
player with the most life or tied for most life, put a
+1/+1 counter on it.)
Whenever Scourge of the Throne attacks for the
first time each turn, if it's attacking the player
with the most life or tied for the most life, untap
all attacking creatures. After this phase, there
is an additional combat phase.