When Deceiver Exarch enters, it triggers, untapping Emry.
Activate Tormod's Crypt by tapping and sacrificing it.
Repeat.
This clever loop centers around Emry, Lurker of the Loch, whose tap ability lets you repeatedly cast Tormod's Crypt straight out of your graveyard for zero mana. Every time you cast that free artifact, Displacer Kitten's passive *Avoidance* ability triggers to blink Deceiver Exarch, which enters the battlefield to untap Emry, Lurker of the Loch and ready her for the next iteration. Tormod's Crypt conveniently sends itself right back to the graveyard when sacrificed, feeding Emry's recursion loop while letting you clear out graveyards infinitely.