Springheart Nantuko | Mutable Explorer | Tireless Provisioner (and one other card)

Cards

All permanents on the battlefield (
Springheart Nantuko attached to
Mutable Explorer).

Play a land.
When the land enters,
Springheart Nantuko triggers, causing you to pay ({1} magic symbol) ({G} magic symbol) to create two token copies of
Mutable Explorer.
When the
Mutable Explorer tokens enter, they trigger.
Resolve the first
Mutable Explorer trigger, creating two Mutavault land tokens that enters tapped.
When the Mutavault tokens enter,
Springheart Nantuko and
Tireless Provisioner each trigger twice.
Resolve the
Tireless Provisioner triggers, creating two Treasure tokens.
Holding priority, activate the Treasures by tapping and sacrificing them, adding ({1} magic symbol) ({G} magic symbol) .
Resolve the
Springheart Nantuko trigger, causing you to pay ({1} magic symbol) ({G} magic symbol) to create two token copies of
Mutable Explorer.
Repeat from step 3.

This combo has been estimated to be Exhibition (Bracket 1+).