Fiend Hunter, Changeling Titan, and Lumbering Battlement

Prerequisites

• Fiend Hunter in hand or on the battlefield or in exile
• Changeling Titan in hand or on the battlefield or in exile
• Lumbering Battlement in hand or on the battlefield or in exile
• plus the mana cost of the creature in your hand available

Steps

1. Cast Fiend Hunter for its mana cost
2. When Fiend Hunter enters, it exiles Changeling Titan until Fiend Hunter leaves the battlefield
3. Resolve any additional effects of Fiend Hunter's ETB
4. When Changeling Titan leaves the battlefield, Lumbering Battlement is returned from exile to the battlefield
5. When Lumbering Battlement enters, it exiles Fiend Hunter until Lumbering Battlement leaves the battlefield
6. Resolve any additional effects of Lumbering Battlement's ETB
7. When Fiend Hunter leaves the battlefield, Changeling Titan is returned from exile to the battlefield
8. When Changeling Titan enters, it exiles Lumbering Battlement until Changeling Titan leaves the battlefield
9. Resolve any additional effects of Changeling Titan's ETB
10. When Lumbering Battlement leaves the battlefield, Fiend Hunter is returned from exile to the battlefield
11. Repeat from step 2

Results

• Infinite creature ETB
• Infinite creature LTB