Gwenna, Eyes of Gaea, Thornbite Staff, Bloodsoaked Champion, and Altar of Dementia

Prerequisites

• Gwenna, Eyes of Gaea on the battlefield
• Thornbite Staff on the battlefield
• Bloodsoaked Champion on the battlefield
• Altar of Dementia on the battlefield
• Thornbite Staff attached to Gwenna
• Gwenna does not have summoning sickness
• A creature has attacked this turn

Steps

1. Activate Altar of Dementia by sacrificing Bloodsoaked Champion
2. Bloodsoaked Champion dies, triggering Gwenna, untapping Gwenna
3. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Bloodsoaked Champion's power
4. Activate Gwenna by tapping it, adding that can only be spent to cast creature spells or activate abilities of creatures
5. Activate Bloodsoaked Champion by paying , returning it from your graveyard to the battlefield
6. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill