Mercurial Pretender Combos
Mercurial Pretender + Dockside Extortionist
Sharuum the Hegemon + Mercurial Pretender
Adarkar Valkyrie + Intruder Alarm + Mercurial Pretender
Volo, Guide to Monsters + Mercurial Pretender + Great Whale
Combo result
Infinite mana lands you control can produce. Infinite creature tokens. Infinite ETB. Infinite LTB. Infinite storm count.
Prerequisites
Mercurial Pretender in hand. All other permanents on the battlefield. You control up to seven lands that can tap to produce at least {U}{U}. You have no other Shapeshifters on the battlefield or in your graveyard.
Volo, Guide to Monsters + Mercurial Pretender + Peregrine Drake
Combo result
Infinite mana lands you control can produce. Infinite creature tokens. Infinite ETB. Infinite LTB. Infinite storm count.
Prerequisites
Mercurial Pretender in hand. All other permanents on the battlefield. You control up to five lands that can tap to produce at least {U}{U}. You have no other Shapeshifters on the battlefield or in your graveyard.