Ketramose, the New Dawn, Lich's Mastery, and Putrid Imp

Prerequisites

• Ketramose, the New Dawn on the battlefield
• Lich's Mastery on the battlefield
• Putrid Imp on the battlefield

Steps

1. Lose life by any method
2. Lich's Mastery's second ability triggers, causing you to exile a card from your graveyard
3. Ketramose triggers, causing you to lose 1 life and draw a card
4. Lich's Mastery second ability triggers
5. Holding priority, activate Putrid Imp by discarding a card
6. Resolve the Lich's Mastery trigger, exiling a card from your graveyard
7. Repeat from step 3

Results

• Exile your library
• Infinite draw triggers
• Infinite rummaging
• Infinite self-discard triggers