Remembrance + Mortuary + Ornithopter + Phantom Train

Remembrance

Mortuary

Ornithopter

Phantom Train

How it works

1. Activate Phantom Train by sacrificing Ornithopter.
2. When Ornithopter dies, Mortuary and Remembrance trigger.
3. Resolve the Mortuary trigger, putting Ornithopter from your graveyard on top of your library.
4. Resolve the Remembrance trigger, searching your library for Ornithopter and putting it into your hand.
5. Resolve the Phantom Train ability.
6. Cast Ornithopter by paying 0.
7. Repeat.

This loop relies on a clever interplay of triggers that turns a single zero-mana artifact into a self-sustaining engine. When you sacrifice Ornithopter to fuel Phantom Train's ability, Mortuary and Remembrance both trigger simultaneously off its death; Mortuary places the tiny flyer right back on top of your library, while Remembrance lets you tutor a second copy straight into your hand. Because Ornithopter costs nothing to cast, you can immediately replay it, creating an endless cycle of creature deaths, enters-the-battlefield events, and sacrifices that permanently pumps up Phantom Train's size.