Kelsien, the Plague, Thornbite Staff, and Sorin, Imperious Bloodlord

Prerequisites

• Kelsien, the Plague on the battlefield
• Thornbite Staff on the battlefield
• Sorin, Imperious Bloodlord on the battlefield
• Thornbite Staff attached to Kelsien

Steps

1. Activate Sorin's first loyalty ability by putting a loyalty counter on it, giving Kelsien deathtouch and lifelink until end of turn
2. Activate Kelsien by tapping it, dealing 1 damage to target creature, destroying it due to Kelsien's deathtouch, and causing you to gain 1 life
3. The creature dies, triggering Kelsien twice
4. Resolve the first Kelsien trigger, causing you to get an experience counter
5. Resolve the second Kelsien trigger, untapping it
6. Repeat

Results

• Destroy any number of target creature(s) opponents control during each of your turns