Feast of Sanity, and Illusory Ambusher

Prerequisites

• Feast of Sanity on the battlefield
• Illusory Ambusher on the battlefield
• You control an effect that can increase Illusory Ambusher's toughness by at least one, or that can give Illusory Ambusher indestructible
• Your hand size is greater than seven, but less than seven plus Illusory Ambusher's toughness

Steps

1. Proceed to your cleanup step, causing you to discard down to your maximum hand size and remove all damage from all permanents
2. Feast of Sanity triggers for each card discarded this way
3. Resolve the first trigger, dealing 1 damage to Illusory Ambusher and causing you to gain one life
4. Illusory Ambusher triggers, causing you to draw a card
5. Repeat from step 3 as necessary for each remaining trigger
6. Once all triggers have been resolved, and all players pass priority, another cleanup step will occur, causing you to discard down to your maximum hand size and remove all damage from all permanents
7. Repeat from step 2

Results

• Infinite draw triggers
• Infinite looting
• Infinite self-discard triggers
• Near-infinite lifegain
• Near-infinite lifegain triggers