Crackdown Construct + Spirit Mirror + Opalescence

Crackdown Construct

Spirit Mirror

Opalescence

How it works

1. Activate Spirit Mirror by paying 0, targeting any Reflection.
2. Crackdown Construct triggers, giving itself +1/+1 until end of turn.
3. Repeat.
4. Resolve all Spirit Mirror abilities, destroying the targeted Reflection(s).

This clever loop turns a classic enchantment into an engine of limitless growth by animating it into a creature. With Opalescence transforming Spirit Mirror into a creature alongside its normal enchantment status, you gain the ability to target any Reflection with Spirit Mirror's zero-cost activation over and over again without ever needing to let the ability resolve. Because Crackdown Construct watches for you to activate any artifact or creature ability that isn't a mana ability, every single repetition of that free target-and-destroy trigger pumps Crackdown Construct's power and toughness higher and higher until it becomes infinitely large for the turn.