Kiki-Jiki, Mirror Breaker + Lumbering Battlement + Phantom Train

Kiki-Jiki, Mirror Breaker

Lumbering Battlement

Phantom Train

How it works

1. Activate Kiki-Jiki by tapping it, creating a token copy of Lumbering Battlement.
2. When the Lumbering Battlement token enters the battlefield, it triggers, exiling Kiki-Jiki until Lumbering Battlement leaves the battlefield.
3. Activate Phantom Train by sacrificing the Lumbering Battlement token.
4. When the Lumbering Battlement token dies, Kiki-Jiki is returned from exile to the battlefield.
5. Resolve the Phantom Train ability.
6. Repeat.

This clever loop begins by using Kiki-Jiki, Mirror Breaker to churn out a hasty copy of Lumbering Battlement, whose entry trigger immediately swallows Kiki-Jiki whole to hide it safely away. To break the beast out and restart the cycle, you feed that Lumbering Battlement token to Phantom Train as a sacrifice cost, which pumps the Train's size with a +1/+1 counter while simultaneously releasing Kiki-Jiki right back onto the battlefield. Because Kiki-Jiki's haste lets it immediately repeat the process, this endless revolving door generates infinite entry, death, and sacrifice triggers alongside an arbitrarily large Phantom Train.