Grazing Kelpie + Hardened Academic + Phyrexian Altar

RGWU identity

Commander legal

The 3 combo pieces

• Grazing Kelpie
• Hardened Academic
• Phyrexian Altar

How to execute it

1. Activate Phyrexian Altar by sacrificing Grazing Kelpie.
2. When Grazing Kelpie 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 Grazing Kelpie.
4. Repeat.

What the combo produces

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