Enduring Renewal + Crystalline Crawler + Sunbond + Pelakka Wurm + Altar of Dementia

Enduring Renewal

Crystalline Crawler

Sunbond

Pelakka Wurm

Altar of Dementia

How it works

1. Cast Pelakka Wurm by paying 4.
2. When Pelakka Wurm enters the battlefield, its first ability triggers, causing you to gain 7 life.
3. Crystalline Crawler triggers, putting seven +1/+1 counters on itself.
4. Activate Crystalline Crawler's first ability seven times by removing seven +1/+1 counters from it, adding 4.
5. Activate Altar of Dementia by sacrificing Pelakka Wurm.
6. When Pelakka Wurm dies, its second ability and Enduring Renewal trigger.
7. Resolve the Pelakka Wurm trigger, causing you to reveal the top card of your library and put it into your graveyard if its a creature card, or draw a card otherwise.
8. Resolve the Enduring Renewal trigger, returning Pelakka Wurm from your graveyard to your hand.
9. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Pelakka Wurm's power.
10. Repeat.

This loop is fueled by Pelakka Wurm's entering-the-battlefield trigger, which grants 7 life and pumps up Crystalline Crawler via Sunbond to continuously supply the mana needed to recast the Wurm. Once your mana is secured, Altar of Dementia sacrifices the Wurm to mill away your opponents while also triggering its death ability. That death is neatly bypassed by Enduring Renewal, which immediately scoops the Wurm back to your hand so you can repeat the whole cycle infinitely.