Mortuary + Cryptic Trilobite + Gwenom, Remorseless

Mortuary

Cryptic Trilobite

Gwenom, Remorseless

How it works

1. Cast Cryptic Trilobite either from your hand by paying 0 or from the top of your library by paying 0 life.
2. Cryptic Trilobite enters and dies as a state-based action due to having 0 toughness.
3. Mortuary triggers, putting Cryptic Trilobite from your graveyard onto the top of your library.
4. Repeat.

This clever loop turns Cryptic Trilobite into an endlessly recurring sacrifice engine by exploiting the fact that it enters the battlefield with zero toughness when cast for zero mana, immediately sending it to the graveyard. Mortuary acts as the glue that catches the dying construct, instantly recycling it from your graveyard back to the top of your library so you can repeat the process indefinitely. Meanwhile, Gwenom, Remorseless enables the whole engine from the command zone or battlefield, letting you play that same Cryptic Trilobite straight off the top of your library while paying life instead of mana.