Cast Dockside Extortionist by paying {1}{R}.
Dockside Extortionist enters the battlefield, creating at least six Treasure tokens.
Cast Lore Drakkis for its mutate cost by paying {U/R}{U/R}, targeting Dockside Extortionist.
Lore Drakkis's mutate ability triggers, returning String of Disappearances from your graveyard to hand.
Cast String of Disappearances by paying {U}, returning Dockside Extortionist and Lore Drakkis to your hand.
Activate five Treasure tokens by tapping and sacrificing those, adding {1}{U}{U/R}{U/R}{R}.
Repeat.

Infinite colored mana

Infinite ETB

Infinite LTB

Combos with "String of Disappearances"