Activate Emry by tapping it, allowing you to cast Welding Jar from your graveyard.
Cast Welding Jar by paying 0.
Displacer Kitten triggers, blinking Emry.
When Emry enters, it triggers, causing you to mill four cards.
Activate Welding Jar by sacrificing it.
Repeat.
This clever loop turns the unassuming Welding Jar into an infinite engine by utilizing Emry, Lurker of the Loch to repeatedly pull the artifact out of the graveyard and cast it. Every time you cast that zero-mana spell, Displacer Kitten triggers to blink Emry, resetting her tap ability and triggering a fresh mill of four cards upon re-entry. Meanwhile, Urabrask the Hidden ensures that your repeatedly blinking Emry can immediately rejoin the action with haste, while its passive text keeps opponents' creatures safely tapped down.