Idris, Soul of the TARDIS + Psychic Battle + Cephalid Illusionist + Encroaching Mycosynth

Prerequisites

• The top card of your library has a higher mana value than the top cards of each opponent's library.
• You have a way to choose one or more targets, as well as additional legal targets for that spell or ability.

Steps

1. 1Cast Idris either from your hand or from the command zone by paying plus commander tax, if applicable.
2. 2When Idris enters the battlefield, it triggers, exiling Psychic Battle until Idris leaves the battlefield.
3. 3Choose any number of targets by any method.
4. 4Idris triggers, causing each player to reveal the top card of their library and changing the target(s) of the spell or ability to Cephalid Illusionist.
5. 5Cephalid Illusionist and Idris trigger.
6. 6Resolve the Cephalid Illusionist trigger, causing you to mill three cards.
7. 7Resolve the Idris trigger, causing each player to reveal the top card of their library and changing the target(s) of the spell or ability to any other target.
8. 8Repeat from step 4.

Effects

• Infinite self-mill