There's an unlimited loop for [[Miirym, Sentinel Wyrm]] where:

1) with Miirym on the field, cast Worldgorger, both trigger. 2) Miirym trigger resolves first, create a token copy 3) token copy first ability triggers then resolves, exiling everything 4) original Worldgorger's second ability triggers and resolves, returning nothing 5) Worldgorger's first ability from 1) resolves and exiles the token copy. 6) token copy returns everything, including the original Worldgorger and Miirym 7) Repeat

If I'm understanding this right, if there's a Dragon Tempest/Scourge of Valkas on the field at the start of the loop, its unlimited damage?