Rek'Sai, Void Burrower

Annihilator 1, First strike, Haste
If Rek'Sai is tapped, he is considered Burrowed.
(If Rek,Sai is Burrowed before your combat step you
may pay {2}{p/r} to untap her, then deal 2 to any target.)
{p/r}: Rek'Sai gets +1/0 until endstep.(up to 3 times.)
Burrowed postcombat; {p/r}{p/r}: Deal 1 to any target, it
gets a Prey counter.(activates only once per turn.)
Burrowed during combat; {4}{p/r}{p/r}:Rek'Sai phases out;
target creature with a Prey counter.When she phases