Phyrexian Altar + Sister Hospitaller + Icewind Stalwart

Phyrexian Altar

Sister Hospitaller

Icewind Stalwart

How it works

1. Cast Icewind Stalwart by paying its mana cost.
2. When Icewind Stalwart enters the battlefield, it triggers, targeting Sister Hospitaller
3. Holding priority, activate Phyrexian Altar by sacrificing Icewind Stalwart.
4. Resolve the Icewind Stalwart ability, blinking Sister Hospitaller
5. When Sister Hospitaller enters, it triggers, returning Icewind Stalwart from your graveyard to the battlefield.
6. Repeat from step 2.