Haru, Hidden Talent, Dryad Arbor, Ashnod's Altar, and Rukarumel, Biologist

Prerequisites

• Haru, Hidden Talent on the battlefield
• Dryad Arbor in hand
• Ashnod's Altar on the battlefield
• Rukarumel, Biologist on the battlefield

Steps

1. Play Dryad Arbor
2. When Dryad Arbor enters as an Ally due to Rukarumel, Haru triggers, earthbending Dryad Arbor
3. Activate Dryad Arbor by tapping it, adding
4. Activate Ashnod's Altar by sacrificing Dryad Arbor
5. When Dryad Abor dies, Haru triggers, returning Dryad Arbor from your graveyard to the battlefield
6. Repeat from step 2

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite colorless mana
• Infinite landfall triggers
• Infinite green mana