Quickbeam, Upstart Ent + Devoted Druid + Ant Queen + Conspiracy

Quickbeam, Upstart Ent

Devoted Druid

Ant Queen

Conspiracy

How it works

1. Activate Devoted Druid's first ability by tapping it, adding .
2. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
3. Activate Devoted Druid's first ability by tapping it, adding .
4. Activate Ant Queen by paying 1, creating a 1/1 Insect creature token.
5. When the Insect enters the battlefield as a Treefolk due to Conspiracy, Quickbeam triggers, giving Devoted Druid and up to one other creature +2/+2 until end of turn.
6. Activate Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
7. Repeat.

This clever loop relies on Conspiracy to rewrite the identity of every creature you own, turning the Insect tokens spawned by Ant Queen into Treefolk the moment they hit the battlefield. That sudden influx of Treefolk triggers Quickbeam, Upstart Ent to continuously pump up your board with massive stat boosts and trample. Meanwhile, Devoted Druid fuels the entire engine by tapping for green mana and untapping itself through its own -1/-1 counter ability, generating the exact mana needed to sustain the queen's insect production over and over again.