Sorcerer's Broom, Krark-Clan Ironworks, and Bard, King of Dale

Prerequisites

• Sorcerer's Broom on the battlefield
• Krark-Clan Ironworks on the battlefield
• Bard, King of Dale on the battlefield
• at most available

Steps

1. Use Krark-Clan Ironworks to sacrifice another creature, or sacrifice a permanent by any other method
2. Sorcerer's Broom triggers, causing you to pay to create two creature tokens due to Bard
3. Activate Krark-Clan Ironworks twice by sacrificing the Sorcerer's Broom tokens, adding
4. Sorcerer's Broom triggers twice, and each Sorcerer's Broom token triggers once
5. Resolve all but one trigger, choosing not to pay
6. Resolve the final trigger, causing you to pay to create two creature tokens
7. Repeat from step 3

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite colorless mana
• Infinite creature tokens
• Infinite death triggers
• Infinite creature sacrifice triggers
• Infinite artifact ETB
• Infinite artifact LTB
• Infinite artifact sacrifice triggers