Jin-Gitaxias and Nyxbloom Ancient on the battlefield.
You control an artifact or land that can tap to produce at least ({U} magic symbol) .
You have not copied a spell with Jin-Gitaxias this turn.
Steps
Activate an artifact or land you control by tapping it, adding at least ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Cast Ghostly Flicker by paying ({2} magic symbol) ({U} magic symbol) , targeting any two permanents.
Jin-Gitaxias triggers, creating a copy of Ghostly Flicker targeting Jin-Gitaxias and any artifact or land that can tap to produce at least ({U} magic symbol) .
Resolve the copy of Ghostly Flicker, blinking Jin-Gitaxias and the artifact or land.
Activate the artifact or land by tapping it, adding at least ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Jin-Gitaxias triggers, creating a copy of Narset's Reversal targeting the original Narset's Reversal.
Resolve the copy of Narset's Reversal, copying the original Narset's Reversal targeting Ghostly Flicker, and returning the original Narset's Reversal to your hand.
Resolve Narset's Reversal, creating a copy of Ghostly Flicker targeting Jin-Gitaxias and the artifact or land, and returning the original Ghostly Flicker to your hand.
Resolve Ghostly Flicker, blinking Jin-Gitaxias and the artifact or land.
Repeat.
Results
Infinite blinking.
Infinite ETB.
Infinite LTB.
Infinite magecraft triggers.
Infinite mana artifacts and lands you control can produce.