The Mindskinner and Soul of Eternity on the battlefield.
An opponent cannot block Soul of Eternity.
Soul of Eternity does not have summoning sickness.
Steps
Declare Soul of Eternity as an attacker.
When Soul of Eternity would deal combat damage to the opponent, The Mindskinner prevents that damage, and causes each opponent to mill that many cards.
Notes
If desired, you may repeat this loop on subsequent turns. You may also attack with other creatures, as able, to cause opponents to mill more cards.