Cast Corpse Dance with buyback by tapping Caetus, Vampire Hexmage and three other creatures you control.
Displacer Kitten triggers, blinking Caetus and causing it to return to the battlefield as Invasion of Segovia.
When Invasion of Segovia enters the battlefield, it triggers, creating four 1/1 Kraken creature tokens.
Activate Vampire Hexmage by sacrificing it, removing all counters from Invasion of Segovia.
Invasion of Segovia triggers, causing you to exile it and cast it as Caetus, Sea Tyrant of Segovia.
Resolve Corpse Dance, returning Vampire Hexmage from your graveyard to the battlefield and returning Corpse Dance to your hand.
Repeat.
This clever loop puts Invasion of Segovia’s front and back faces to brilliant work by repeatedly flipping the battle using Vampire Hexmage to strip its defense counters. With Anointed Procession doubling the Kraken tokens produced when the Siege enters, and Invasion of Segovia granting your spells convoke, you can easily tap those very tokens alongside other creatures to pay for Corpse Dance with buyback. Meanwhile, Displacer Kitten ensures that every time you cast Corpse Dance, it blinks the Siege to reset its trigger, allowing you to seamlessly cycle Vampire Hexmage back from the graveyard for an infinite storm of magical energy and token armies.