Ratadrabik of Urborg + Boonweaver Giant + On Serra's Wings + Altar of Dementia

Ratadrabik of Urborg

Boonweaver Giant

On Serra's Wings

Altar of Dementia

How it works

1. Activate Altar of Dementia by sacrificing Boonweaver Giant.
2. When Boonweaver Giant dies as a legendary creature due to On Serra's Wings, Ratadrabik of Urborg triggers, creating a token copy of Boonweaver Giant that is a 2/2 Zombie in addition to its other types.
3. When the Boonweaver Giant token enters the battlefield, it triggers, returning On Serra's Wings from your graveyard to the battlefield attached to the token.
4. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Boonweaver Giant's power.
5. Repeat.

This loop transforms Boonweaver Giant into an endless mill engine by leveraging On Serra's Wings to grant the giant the legendary status required to fuel Ratadrabik of Urborg's zombie-copy trigger. When you sacrifice the giant to Altar of Dementia, Ratadrabik steps in to replace it with a non-legendary copy that immediately fetches On Serra's Wings back from the graveyard upon entering the battlefield. Because the newly attached Aura makes this token legendary all over again, you can feed it right back into Altar of Dementia to repeat the entire cycle indefinitely.