Infinite combat damageInfinite combat phasesInfinite damageOpponents discard their handsInfinite mana lands you control can produceInfinite untap of lands you control
How it works
Declare Hellkite Charger as an attacker.
Hellkite Charger triggers.
In response, activate lands you control by tapping them, adding at least 5.
Resolve Hellkite Charger's trigger, paying 5 to gain an extra combat phase and untap all attacking creatures you control.
When Hellkite Charger deals combat damage, Sword of Feast and Famine triggers, untapping all lands you control and causing the defending player to discard a card.