Opponents control at least four artifacts and/or enchantments.
({2} magic symbol) ({R} magic symbol) available.
Steps
Activate Feldon by paying ({2} magic symbol) ({R} magic symbol) and tapping it, creating a token copy of Dockside Extortionist that is an artifact in addition to its other types.
When Dockside Extortionist enters the battlefield, it triggers, creating at least four Treasure tokens.
Activate three Treasures by tapping and sacrificing them, adding ({2} magic symbol) ({R} magic symbol) .
Activate Altar of Dementia by sacrificing Dockside Extortionist.
When Dockside Extortionist dies, Feldon triggers, untapping Feldon.
Resolve the Altar of Dementia ability, causing target player to mill cards equal to Dockside Extortionist's power.