Arcbound Reclaimer, Showdown of the Skalds, Lion's Eye Diamond, and Bolas's Citadel

Prerequisites

• Arcbound Reclaimer on the battlefield
• Showdown of the Skalds on the battlefield or in the graveyard
• Lion's Eye Diamond in hand or in the library
• Bolas's Citadel on the battlefield

Steps

1. Cast Lion's Eye Diamond either from your hand by paying or from the top of your library by paying 0 life
2. Showdown of the Skalds triggers, putting a +1/+1 counter on Arcbound Reclaimer
3. Activate Lion's Eye Diamond by discarding your hand and sacrificing it
4. Activate Arcbound Reclaimer by removing a +1/+1 counter from it, putting Lion's Eye Diamond from your graveyard onto the top of your library
5. Repeat

Results

• Infinite colored mana
• Infinite +1/+1 counters on a creature
• Infinite +1/+1 counters on Golems you control