Hardened Tactician, The Watcher in the Water, and Pitiless Plunderer

Prerequisites

• Hardened Tactician on the battlefield
• The Watcher in the Water on the battlefield
• Pitiless Plunderer on the battlefield
• undefined if you don't control a creature token or otherwise available

Steps

1. Activate Hardened Tactician by paying and sacrificing a token
2. If you sacrificed a creature token, Pitiless Plunderer triggers, and The Watcher's second ability triggers if the creature token was a Tentacle
3. Resolve the Pitiless Plunderer trigger, if applicable, creating a Treasure token
4. Resolve the Watcher trigger, if applicable, untapping a Kraken and putting a stun counter on up to one nonland permanent
5. Resolve the Hardened Tactician ability, causing you to draw a card
6. The Watcher's first ability triggers, creating a 1/1 Tentacle creature token
7. If you control a Treasure, activate it by tapping and sacrificing it, adding
8. Repeat

Results

• Infinite card draw
• Near-infinite ETB
• Infinite draw triggers
• Near-infinite LTB
• Near-infinite death triggers
• Near-infinite sacrifice triggers
• Near-infinite untap of Krakens you control