Hei Bai, Forest Guardian, Phyrexian Altar, and Umbral Mantle

Prerequisites

• Hei Bai, Forest Guardian on the battlefield
• Phyrexian Altar on the battlefield
• Umbral Mantle on the battlefield
• available

Steps

1. Activate Hei Bai by paying and tapping it, creating a 1/1 Spirit creature token for each legendary enchantment you control
2. Activate Phyrexian Altar eight times by sacrificing eight Spirits, adding
3. Activate Hei Bai by paying and untapping it, giving it +2/+2 until end of turn
4. Repeat

Results

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