Crackdown Construct, and Soltari Guerrillas

Prerequisites

• Crackdown Construct on the battlefield
• Soltari Guerrillas on the battlefield

Steps

1. Activate Soltari Guerrillas's ability targeting a creature
2. Crackdown Construct gets +1/+1 until end of turn
3. Repeat

Results

• Infinitely large Crackdown Construct