March of the Hellbound

March of the Hellbound enters the battlefield with X Death counters on it.
{b}{b},{t}: Add one Death counter to March of the Hellbound.
{3}{b}: Put X 2/2 Black Zombie creature tokens on the battlefield tapped.
{b}, Remove X death counters: But an X/X Black Demon on the battlefield, where X is the number of Death counters removed this way.