Hardened Academic + Phyrexian Altar + Twilight Shepherd

RW identity

Commander legal

The 3 combo pieces

• Hardened Academic
• Phyrexian Altar
• Twilight Shepherd

How to execute it

1. Activate Phyrexian Altar by sacrificing Twilight Shepherd.
2. When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Hardened Academic triggers, putting a +1/+1 counter on Twilight Shepherd.
4. Repeat.

What the combo produces

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