Elemental Mastery, Nurturing Presence, and Barrenton Medic

Prerequisites

• Elemental Mastery on the battlefield
• Nurturing Presence on the battlefield
• Barrenton Medic on the battlefield
• Elemental Mastery and Nurturing Presence attached to Barrenton Medic
• Barrenton Medic does not have summoning sickness, and has a power of one or greater

Steps

1. Activate Barrenton Medic by tapping it, creating at least one 1/1 Elemental creature token with haste
2. When the Elemental token(s) enter the battlefield, Barrenton Medic triggers that many times, giving it +1/+1 until end of turn for each creature that entered the battlefield
3. Activate Barrenton Medic by putting a -1/-1 counter on it, untapping it
4. Repeat
5. If Barrenton Medic has a power of two or greater, it also becomes infinitely large until end of turn

Results

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