Kiora's Follower, Judge of Currents, and Mercurial Pretender

Prerequisites

• Kiora's Follower on the battlefield
• Judge of Currents on the battlefield
• Mercurial Pretender on the battlefield
• Mercurial Pretender is a copy of Kiora's Follower
• Kiora's Follower and Mercurial Pretender do not have summoning sickness

Steps

1. Activate Kiora's Follower by tapping it
2. When Kiora's Follower becomes tapped, Judge of Currents triggers, causing you to gain 1 life
3. Resolve Kiora's Follower's ability from step 1, untapping Mercurial Pretender
4. Activate Mercurial Pretender by tapping it
5. When Mercurial Pretender becomes tapped, Judge of Currents triggers, causing you to gain 1 life
6. Resolve Mercurial Pretender's ability from step 4, untapping Kiora's Follower
7. Repeat

Results

• Infinite lifegain
• Infinite lifegain triggers