Basri's Lieutenant + Master Biomancer + Altar of Dementia

Basri's Lieutenant

Master Biomancer

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing another creature with a +1/+1 counter on it.
2. When the creature dies, Basri's Lieutenant's second ability triggers, creating a 2/2 Knight creature token that enters the battlefield with at least two +1/+1 counters due to Master Biomancer.
3. Resolve the Altar of Dementia ability, causing target player to mill cards equal to the sacrificed creature's power.
4. Repeat.

This loop relies on an ingenious scaling effect where Master Biomancer acts as the catalyst, ensuring every new token enters the battlefield with extra +1/+1 counters based on its own growing power. When you sacrifice a creature using Altar of Dementia, Basri's Lieutenant triggers upon its death to replace it with a fresh 2/2 Knight token. Because of the Biomancer's static pump, that replacement token arrives large enough to immediately fuel the Altar for another sacrifice, perpetuating an endless cycle of death and mill.