Feldon of the Third Path + Worldgorger Dragon + The Fire Crystal + Gogo, Master of Mimicry

Feldon of the Third Path

Worldgorger Dragon

The Fire Crystal

Gogo, Master of Mimicry

How it works

1. Activate any number of permanents by tapping them, adding at least 4.
2. Activate Feldon by paying 2 and tapping it, targeting Worldgorger Dragon.
3. Holding priority, activate Gogo by paying 2 and tapping it, copying Feldon's ability targeting Worldgorger Dragon.
4. Resolve the copy of Feldon's ability, creating a token copy of Worldgorger Dragon.
5. When the Worldgorger Dragon token enters, its first ability triggers, exiling all other permanents you control.
6. Resolve the Feldon ability from step 2, creating a token copy of Worldgorger Dragon.
7. When the Worldgorger Dragon token enters, its first ability triggers, exiling all other permanents you control.
8. When the Worldgorger Dragon token created in step 4 leaves the battlefield, its second ability triggers, returning all cards exiled with it to the battlefield.
9. Repeat.

This ingenious loop is anchored by Feldon of the Third Path, whose ability to spin up artifact token copies of creatures in your graveyard is usually kept in check by the end-step sacrifice clause. However, by using Gogo, Master of Mimicry to instantly copy Feldon’s activation targeting Worldgorger Dragon, you set off a cascade of entering and leaving the battlefield. Every time a Worldgorger Dragon token enters, its triggered ability exiles your entire board—including Feldon of the Third Path, Gogo, Master of Mimicry, and any lands or mana rocks you tapped to fuel the setup—which immediately forces the previous Dragon to leave the battlefield and return everything untapped. Meanwhile, The Fire Crystal quietly ensures your creatures keep their haste and your red spells cost less, though its own activated ability isn't even needed once Worldgorger Dragon begins endlessly looping your mana sources to restart the cycle.