Atla Palani, Nest Tender + Mirror Entity + Worldspine Wurm

Atla Palani, Nest Tender

Mirror Entity

Worldspine Wurm

How it works

1. Increase Atla's toughness by at least one.
2. Activate Mirror Entity an arbitrarily large number of times by paying a total of 0.
3. Resolve the first Mirror Entity ability, causing all creatures you control to have base power and toughness 0/0 and gain all creature types until end of turn.
4. All creatures you control except Atla die as a state-based action due to having zero toughness.
5. If Worldspine Wurm died this way, it triggers, shuffling itself into your library.
6. Atla triggers once for each creature that died.
7. Resolve the first Atla trigger, revealing cards from the top of your library until you reveal a creature card, then putting the creature card onto the battlefield and all other revealed cards on the bottom of your library.
8. Repeat step 7 for each remaining Atla trigger.
9. Repeat from step 3 for each remaining Mirror Entity ability.

This clever loop turns Mirror Entity's flexible scaling into a self-contained executioner's block for your own board, leveraging the changeling ability to make every creature you control an Egg. With Atla Palani, Nest Tender tapping to fuel the initial token creation or simply presiding over the carnage, zeroing out your creatures' toughness causes them to instantly perish as state-based actions. Because Worldspine Wurm counts as an Egg under Mirror Entity's effect, its death triggers Atla Palani's ability to cheat giant threats directly into play while its own replacement/triggered ability recycles it back into your library, ensuring you never run out of fuel.