Insidious Roots + Nether Traitor + Phyrexian Altar

BG identity

Commander legal

The 3 combo pieces

• Insidious Roots
• Nether Traitor
• Phyrexian Altar

How to execute it

1. Activate Phyrexian Altar by sacrificing Nether Traitor, adding one mana of any color.
2. Activate Phyrexian Altar by sacrificing another creature, adding {B}.
3. When the creature dies, Nether Traitor triggers, causing you to pay {B} to return it from your graveyard to the battlefield.
4. Insidious Roots triggers, creating a creature token.
5. Repeat.

What the combo produces

• Infinite +1/+1 counters on certain creatures
• Infinite colored mana
• Infinite creature LTB
• Infinite death triggers
• Infinite ETB
• Infinite sacrifice triggers