Ichor of Yawgmoth

Ichor of Yawgmoth enters the battlefield with a Poison counter on it for each {b} spent to cast it.
Whenever a creature dies, put a Poison counter on Ichor of Yawgmoth.
{t}: Move a counter from Ichor of Yawgmoth to target opponent.
A vile legacy festers in the Aboretum vault, waiting to spread once more.