When Corridor Monitor enters, it triggers, untapping Emry.
Activate Dark Sphere by tapping and sacrificing it.
Repeat.
This clever loop turns graveyard recursion into a self-sustaining engine by letting Emry, Lurker of the Loch recast the zero-mana Dark Sphere straight from your graveyard. Each time you cast that artifact, Displacer Kitten’s avoidance trigger blinks Corridor Monitor, whose own entrance ability untaps Emry to do it all over again. Dark Sphere even provides a handy sacrifice outlet along the way, letting you churn through your graveyard and build an unstoppable storm count.