Activate Emry by tapping it, allowing you to cast Lion's Eye Diamond from your graveyard.
Cast Lion's Eye Diamond by paying 0.
Displacer Kitten triggers, blinking Emry.
When Emry enters, it triggers, causing you to mill four cards.
Activate Lion's Eye Diamond by discarding your hand and sacrificing it.
Repeat.
This clever loop puts Displacer Kitten right at the center of the operation, turning every noncreature spell you cast into a handy blink for your creatures. By using Emry, Lurker of the Loch to continuously pull Lion's Eye Diamond right back out of your graveyard, you can cast the diamond for free to trigger the Kitten—refreshing Emry with a fresh entry and a fresh mill of four cards. That endless cycle lets you crack Lion's Eye Diamond for a mountain of mana over and over again, easily sustaining the loop while supporting high-impact finishers like Dragonlord Kolaghan to close out the game.