Marauder, Corrupted Sentinel

Haste
Whenever Marauder, Corrupted Sentinel attacks
you may sacrifice another creature you control.
If you do put a +1/+1 counter on Marauder, Corrupted Sentinel and it gains lifelink until end
of turn.
When Marauder, Corrupted Sentinel leaves the battlefield add {r} equal to its power. You don't
lose this mana as step and phases end.