Felidar Guardian + Dominion Saboteur

Felidar Guardian

Dominion Saboteur

How it works

1. Cast Dominion Saboteur by paying its mana cost, choosing to have it enter the battlefield as a copy of Felidar Guardian
2. When Dominion Saboteur enters the battlefield, it triggers, blinking Felidar Guardian.
3. When Felidar Guardian enters the battlefield, it triggers, blinking Dominion Saboteur. Choose to have Dominion Saboteur enter the battlefield as a copy of Felidar Guardian.
4. Repeat from step 2.