Crackdown Construct, Song of Freyalise, and Endling

Prerequisites

• Crackdown Construct on the battlefield
• Song of Freyalise on the battlefield
• Endling on the battlefield
• Endling does not have summoning sickness
• Song of Freyalise has one or two lore counters on it

Steps

1. Activate Endling by tapping it, adding
2. Activate Endling's first ability by paying
3. Crackdown Construct triggers, giving itself +1/+1 until end of turn
4. Resolve the Endling ability, untapping it
5. Repeat

Results

• Infinitely large Crackdown Construct until end of turn