Crackdown Construct, and Vish Kal, Blood Arbiter

Prerequisites

• Crackdown Construct on the battlefield
• Vish Kal, Blood Arbiter on the battlefield

Steps

1. Activate Vish Kal's second ability by removing all +1/+1 counters from it, targeting any creature
2. Crackdown Construct triggers, giving itself +1/+1 until end of turn
3. Resolve the Vish Kal ability, giving the targeted creature -1/-1 until end of turn for each counter removed from Vish Kal
4. Repeat
5. Once you have an infinitely large Crackdown Construct, you may sacrifice it to Vish Kal's first ability to put infinite +1/+1 counters on it

Results

• Infinite +1/+1 counters on Vish Kal
• Infinitely large Crackdown Construct until end of turn