Great Oak Guardian + Pulsemage Advocate + Altar of Dementia

Prerequisites

• Pulsemage Advocate does not have summoning sickness.

Steps

1. 1Activate Altar of Dementia by sacrificing Great Oak Guardian, causing target opponent to mill four cards.
2. 2Activate Pulsemage Advocate by tapping it and putting three cards from an opponent's graveyard into their owner's hand, returning Great Oak Guardian from your graveyard to the battlefield.
3. 3Great Oak Guardian enters the battlefield, untapping all creatures and giving creatures you control +2/+2 until end of turn.
4. 4Repeat.

Effects

• Infinite card draw for opponents
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control
• Infinitely large creatures you control until end of turn