Cast Corpse Dance with buyback by tapping Caetus, Vampire Hexmage and one other creature 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 two 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 intricate loop harnesses the cost-reducing power of Arcane Melee to make casting Corpse Dance affordable, while Invasion of Segovia’s static ability grants your spells convoke so you can tap your creatures to help pay for them. When you cast Corpse Dance, Displacer Kitten triggers to blink Caetus, Sea Tyrant of Segovia back as the back face of Invasion of Segovia, generating fresh Kraken tokens and resetting its defense counters. You then sacrifice Vampire Hexmage to immediately strip those remaining counters off the Siege, triggering its transformation back into Caetus and fueling an endless cycle that endlessly recurs Vampire Hexmage from the graveyard.