Woodcaller Automaton + Temur Sabertooth + Ashaya, Soul of the Wild + Rainveil Rejuvenator

Woodcaller Automaton

Temur Sabertooth

Ashaya, Soul of the Wild

Rainveil Rejuvenator

How it works

1. Activate Rainveil Rejuvenator by tapping it, adding at least six .
2. Cast Woodcaller Automaton for its prototype cost by paying 2.
3. When Woodcaller Automaton enters, it triggers, untapping Rainveil Rejuvenator
4. Activate Temur Sabertooth by paying 1, returning Woodcaller Automaton from the battlefield to your hand.
5. Repeat.

This elegant loop transforms the battlefield into a self-sustaining mana engine, fueled by Ashaya, Soul of the Wild turning every nontoken creature you control into a Forest land in addition to its other types. With Ashaya's static ability active, casting Woodcaller Automaton for its prototype cost triggers its entry ability to untap a land, which can be Rainveil Rejuvenator thanks to its newfound land type (or Rainveil Rejuvenator's own tap ability if large enough). Temur Sabertooth then steps in to bounce the Automaton back to your hand for a modest mana fee, allowing you to replay it repeatedly. Because Rainveil Rejuvenator taps to produce massive amounts of green mana based on its power, you easily generate a surplus while looping the Automaton infinitely.