The Last Agni Kai, and Jumbo Cactuar

Prerequisites

• The Last Agni Kai in hand
• Jumbo Cactuar on the battlefield
• available

Steps

1. Declare Jumbo Cactuar as an attacker, triggering its ability, giving it +9999/+0 until end of turn
2. Holding priority, cast The Last Agni Kai by paying , causing Jumbo Cactuar to fight a creature an opponent controls, and causing you to gain an amount of equal to the excess damage
3. You won't lose this mana as steps and phases end this turn

Results

• Near-infinite red mana
• Near-infinitely powerful creature until end of turn