Cavalier of Night + Glasspool Mimic // Glasspool Shore + Altar of Dementia

Cavalier of Night

Glasspool Mimic // Glasspool Shore

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Glasspool Mimic.
2. When Glasspool Mimic dies, its second ability triggers, returning itself to the battlefield as a copy of Cavalier of Night.
3. When Glasspool Mimic enters the battlefield, its first ability triggers, choose not to sacrifice a creature.
4. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Glasspool Mimic's power.
5. Repeat.