Cause a nontoken creature to enter the battlefield under your control, which enters as a copy of Sepulchral Primordial due to Infinite Reflection.
When the creature enters, it triggers. Holding priority, activate Woe Strider by sacrificing the creature.
Resolve the creature's trigger, putting a creature card from an opponent's graveyard onto the battlefield under your control as a copy of Sepulchral Primordial.