Hylda of the Icy Crown, Intruder Alarm, Ashnod's Altar, and Court Street Denizen

Prerequisites

• Hylda of the Icy Crown on the battlefield
• Intruder Alarm on the battlefield
• Ashnod's Altar on the battlefield
• Court Street Denizen on the battlefield
• An opponent controls a creature
• You have a way to cause a white creature to enter the battlefield under your control

Steps

1. Cause a white creature to enter the battlefield under your control
2. Intruder Alarm and Court Street Denizen trigger
3. Resolve the Intruder Alarm trigger, untapping all creatures
4. Holding priority, activate Ashnod's Altar by sacrificing the white creature, adding
5. Resolve the Court Street Denizen trigger, tapping an opponent's creature
6. Hylda of the Icy Crown triggers, causing you to pay to create a 4/4 Elemental creature token
7. Repeat from step 2
8. Once you have infinite mana, you may forego sacrificing the Elemental tokens

Results

• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite sacrifice triggers
• Infinite untap of all creatures