Splinter Twin, Nurturing Presence, and Barrenton Medic

Prerequisites

• Splinter Twin on the battlefield
• Nurturing Presence on the battlefield
• Barrenton Medic on the battlefield
• Splinter Twin and Nurturing Presence attached to Barrenton Medic
• Barrenton Medic does not have summoning sickness

Steps

1. Activate Barrenton Medic by tapping it, creating a token copy of itself with haste
2. When the Barrenton Medic token enters the battlefield, the nontoken Barrenton Medic triggers, giving itself +1/+1 until end of turn
3. Activate Barrenton Medic by putting a -1/-1 counter on it, untapping it
4. Repeat

Results

• Infinite creature tokens with haste
• Infinite ETB
• Infinitely powerful Barrenton Medic until end of turn