Shalai and Hallar, and Twinblade Paladin

Prerequisites

• Shalai and Hallar on the battlefield
• Twinblade Paladin on the battlefield
• You have a way to give Shalai and Hallar lifelink
• You have a way to put a +1/+1 counter on a creature you control

Steps

1. Put a +1/+1 counter on a creature you control
2. Shalai and Hallar triggers, dealing 1 damage to an opponent and causing you to gain one life
3. Twinblade Paladin triggers, putting a +1/+1 counter on itself
4. Repeat from step 2

Results

• Infinite +1/+1 counters on Twinblade Paladin
• Infinite damage
• Infinite lifegain
• Infinite lifegain triggers