Soldevi Adnate, Nim Deathmantle, and Great Oak Guardian

Prerequisites

• Soldevi Adnate on the battlefield
• Nim Deathmantle on the battlefield
• Great Oak Guardian on the battlefield
• Soldevi Adnate does not have summoning sickness
• Nim Deathmantle attached to Great Oak Guardian

Steps

1. Activate Soldevi Adnate by tapping it and sacrificing Great Oak Guardian, adding an amount of equal to Great Oak Guardian's mana value
2. When Great Oak Guardian dies, Nim Deathmantle triggers, causing you to pay to return Great Oak Guardian from your graveyard to the battlefield, and attach Nim Deathmantle to it
3. When Great Oak Guardian enters the battlefield, it triggers, untapping all creatures you control and giving them +2/+2 until end of turn
4. Repeat

Results

• Infinite black mana
• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite untap of creatures you control
• Infinite mana creatures you control can produce
• Infinitely large creatures you control until end of turn