The Watcher in the Water, Wylie Duke, Atiin Hero, Heart of Kiran, Phyrexian Altar, and Rukarumel, Biologist

Prerequisites

• The Watcher in the Water on the battlefield
• Wylie Duke, Atiin Hero on the battlefield
• Heart of Kiran on the battlefield
• Phyrexian Altar on the battlefield
• Rukarumel, Biologist on the battlefield
• Wylie Duke does not have summoning sickness
• It is an opponent's turn

Steps

1. During an opponent's turn, activate Heart of Kiran by tapping Wylie Duke
2. Wylie Duke triggers, causing you to draw a card and gain 1 life
3. The Watcher's first ability triggers, creating a 1/1 Tentacle creature token
4. Resolve the Heart of Kiran ability, causing it to become a creature until end of turn
5. Activate Phyrexian Altar by sacrificing the Tentacle
6. adding one mana of any color
7. When the Tentacle dies, The Watcher's second ability triggers, untapping Wylie Duke and putting a stun counter on up to one permanent
8. Repeat

Results

• Infinite card draw
• Near-infinite lifegain
• Near-infinite lifegain triggers
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite death triggers
• Near-infinite sacrifice triggers
• Near-infinite colored mana
• Infinite draw triggers