Pitiless Plunderer and Altar of Dementia on the battlefield.
You have sacrificed at least three artifacts and/or creatures this turn, plus an additional artifact or creature for each time you've cast Dargo from the command zone this game.
({R} magic symbol) available.
Steps
Cast Dargo from the command zone by paying ({R} magic symbol) .
Activate Altar of Dementia by sacrificing Dargo.
Choose to put Dargo into the command zone from your graveyard.
When Dargo dies, Pitiless Plunderer triggers, creating a Treasure token.
Resolve the Altar of Dementia ability, causing target player to mill cards equal to Dargo's power.
Activate the Treasure token by tapping and sacrificing it, adding ({R} magic symbol) .