Ixnir, Undead Overseer

Pay {b/r} X times, Sacrifice X creatures: Create X
2/1 black Skeleton creature tokens with double
strike named Ixnir's Lackey.
{b/r}{b/r}, Sacrifice a Land: Skeletons you control
gain undying until end of turn.
From the depths of the chasms
Comes the army from below