Skulk. (This creature can’t be blocked by creatures with greater power.)

Whenever Xuna deals combat damage to an opponent, the base power of a creature that opponent controls becomes 0 until your next turn.

Your opponents' activated abilities cost {1} more.

{U}{B}{W}, {t}: Target creature gets -X/-0 until end of turn, where X is Xuna's power. If that creature dies this turn, its controller loses 1 life and you gain 1 life.