Beledros Witherbloom, Urza's Saga, Agatha's Soul Cauldron, Arwen, Weaver of Hope, and Gristleback

Prerequisites

• Beledros Witherbloom in exile
• Urza's Saga on the battlefield
• Agatha's Soul Cauldron on the battlefield
• Arwen, Weaver of Hope on the battlefield
• Gristleback in exile
• Urza's Saga has two lore counters on it
• Lands you control except Urza's Saga can tap to produce at least
• Your life total is at least 11
• The number of artifacts you control plus Arwen's toughness is equal to or greater than 9

Steps

1. Activate any number of lands except Urza's Saga by tapping them, adding at least
2. Activate Urza's Saga's second ability by paying and tapping it, creating a 0/0 Construct artifact creature token that gets +1/+1 for each artifact you control, and that enters the battlefield with a number of +1/+1 counters equal to Arwen's toughness
3. Activate the Construct using Beledros Witherbloom's ability by paying 10 life, untapping all lands you control
4. Activate the Construct using Gristleback's ability by sacrificing it, causing you to gain at least 10 life
5. Repeat
6. If the number of artifacts you control plus Arwen's toughness is equal to or greater than 10, this combo nets infinite life, and if other lands you control can tap to produce at least , this combo nets infinite mana
7. If you get infinite life and infinite mana, you may forego sacrificing the Constructs

Results

• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite lifegain
• Infinite lifegain triggers
• Infinite LTB
• Infinitely large Construct tokens
• Infinite mana lands you control can produce
• Infinite sacrifice triggers
• Infinite untap of lands you control