Opponents control at least five artifacts and/or enchantments.
Dockside Extortionist does not have a +1/+1 counter on it.
Steps
Activate Altar of Dementia by sacrificing Dockside Extortionist.
When Dockside Extortionist dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
When Dockside Extortionist enters the battlefield, it triggers, creating at least five Treasure artifact tokens.
Resolve the Altar of Dementia ability from step 1, causing target player to mill cards equal to Dockside Extortionist's power.
Activate five Treasures by tapping and sacrificing them, adding ({4} magic symbol) ({W} magic symbol) .
Activate Resourceful Defense by paying ({4} magic symbol) ({W} magic symbol) , moving all +1/+1 counters from Dockside Extortionist onto another permanent you control.
Repeat.
If opponents control six or more artifacts and/or enchantments, this combo nets infinite Treasure tokens and colored mana.