Guilty Conscience + Phyrexian Vindicator

Prerequisites

Guilty Conscience attached to Phyrexian Vindicator. You have a way to attempt to deal damage to Phyrexian Vindicator.

Steps

1. Attempt to deal any amount of damage to Phyrexian Vindicator.
2. Phyrexian Vindicator prevents the damage and triggers, dealing that much damage to any target.
3. Guilty Conscience triggers, attempting to deal that much damage to Phyrexian Vindicator.
4. Repeat from step 2.