Mikaeus, the Unhallowed, Woe Strider, and Gravelgill Axeshark

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Woe Strider on the battlefield
• Gravelgill Axeshark on the battlefield

Steps

1. Activate Woe Strider by sacrificing Gravelgill Axeshark
2. When Gravelgill Axeshark dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Resolve the Woe Strider ability
4. Activate Woe Strider by sacrificing Gravelgill Axeshark
5. When Gravelgill Axeshark dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. Resolve the Woe Strider ability
7. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite scry 1