Xavier Sal, Infested Captain + Experiment Kraj + Devoted Druid + Aphetto Alchemist

Xavier Sal, Infested Captain

Experiment Kraj

Devoted Druid

Aphetto Alchemist

How it works

1. Activate Experiment Kraj using Devoted Druid's second ability by putting a -1/-1 counter on it, untapping it.
2. Activate Xavier Sal's first ability by tapping it and removing a -1/-1 counter from Experiment Kraj, creating a copy of any creature token you control.
3. Activate Experiment Kraj using Aphetto Alchemist's ability by tapping it, untapping Xavier Sal.
4. Repeat.

This engine transforms a clever arrangement of biological specimens into an unstoppable loop by letting Experiment Kraj borrow the activated abilities of every creature sharing its laboratory. Devoted Druid provides the untap engine by taking on -1/-1 counters, while Aphetto Alchemist chips in to keep the loop going by untapping Xavier Sal. In turn, Xavier Sal uses that precise removal of the -1/-1 counters on Experiment Kraj to fuel his populate ability, flooding the board with infinite creature tokens and endless enter-the-battlefield triggers.