Spellbinder + Great Train Heist + Sylvan Awakening
Spellbinder
Great Train Heist
Sylvan Awakening
Infinite storm countInfinite combat phasesInfinite mana lands you control can produceInfinite untap of creatures you controlInfinite mana creatures you control can produceInfinite magecraft triggersInfinite combat damageInfinite untap of lands you control
How it works
Cast Sylvan Awakening by paying 2, causing all lands you control to become creatures with haste until end of turn.
Deal combat damage with the creature that has Spellbinder attached, triggering Spellbinder.
Holding priority, activate any number of creatures and/or lands you control by tapping them, adding at least 2.
Resolve the Spellbinder trigger, casting a copy of Great Train Heist without paying its mana cost, and choosing to pay an additional 2 to select its first mode, causing you to untap all creatures you control and to get an additional combat phase after this one.