Oathkeeper, Takeno's Daisho, Phyrexian Altar, and Swordsman, Sharp Scoundrel

Prerequisites

• Oathkeeper, Takeno's Daisho on the battlefield
• Phyrexian Altar on the battlefield
• Swordsman, Sharp Scoundrel on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing the creature with changeling, adding one mana
2. When that creature dies, Oathkeeper triggers, returning it from your graveyard to the battlefield
3. When that creature enters, Swordsman triggers, allowing you to attach Oathkeeper to that creature
4. Repeat

Results

• Infinite colored mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers