Blossoming Tortoise + Dryad Arbor + Infinite Reflection + Phyrexian Altar

Blossoming Tortoise

Dryad Arbor

Infinite Reflection

Phyrexian Altar

How it works

1. Play Dryad Arbor.
2. When Dryad Arbor enters the battlefield as a copy of Blossoming Tortoise due to Infinite Reflection, it triggers.
3. Holding priority, activate Phyrexian Altar by sacrificing Dryad Arbor, adding one mana of any color.
4. Resolve the Dryad Arbor trigger from step 2, causing you to mill three cards and return Dryad Arbor from your graveyard to the battlefield.
5. Repeat from step 2.

This clever loop centers around Infinite Reflection, which acts as a permanent copy-engine by forcing all your other nontoken creatures to enter the battlefield as exact copies of the enchanted creature. By starting with Dryad Arbor, you ensure that every land you play automatically enters as a copy of whatever creature is enchanted. Once that creature is Blossoming Tortoise, its entry trigger instantly mills your library and pulls a land back from the graveyard, while its passive ability provides a nice stat boost. The real magic happens with Phyrexian Altar, which lets you instantly sacrifice that land-creature for mana the moment it hits the field, triggering the Tortoise's recursion loop to bring it right back endlessly.