When Flash Thompson enters, it triggers, untapping Emry.
Activate Dark Sphere by tapping and sacrificing it.
Repeat.
This clever loop uses Emry, Lurker of the Loch to continuously pull Dark Sphere out of your graveyard for free, thanks to its zero-mana cost. Every time you cast that artifact, Displacer Kitten triggers to blink Flash Thompson, Spider-Fan out of and back into play. That fresh entry lets Flash Thompson, Spider-Fan untap Emry, Lurker of the Loch so you can tap her again to repeat the entire sequence. Dark Sphere even cushions your life total along the way, letting you safely rack up endless artifact and creature triggers.