Spoilers: Harkon’s background and the origin of his fractured personality.

A realm crewed by the dead
Harkon established his domain on the coast of Lustria. Shipwrecks supplied more than salvage: the dead could be raised into the crews of his pirate fleet. His territory became known as the Vampire Coast, linking his name to the undead raiders who sailed from it.
The chamber that broke his mind
Seeking greater power, Harkon tried to force his way into ancient chambers with dark magic. Protective glyphs turned that attempt against him. He escaped, but his connection to the Winds of Magic was broken and his mind fractured into competing personalities.
Those personalities share a purpose: taking Lizardmen artefacts in the hope of repairing the damage. His piracy and attacks on sacred places therefore serve both ambition and an obsession with recovering the mind he lost.
Harkon in Immortal Empires
In Immortal Empires, Harkon leads The Awakened, one of the Vampire Coast factions unlocked by Curse of the Vampire Coast. His changing personality traits carry that background into the campaign.
Arch Grand Commodore
The Academy gives him the rank the faction starts from. For centuries, Arch Grand Commodore Luthor Harkon has ruled a stretch of Lustrian shore known as the Vampire Coast. Shipwrecks feed the fleet, because the dead can be raised into crews. Expeditions go inland, and pirate voyages cross the Great Ocean. Curse of the Vampire Coast is the pack. The Awakened is the faction. Personality traits on the campaign are the broken mind, played as a shifting lord rather than as a single mood.
He does not cast. The roster reveal calls that out beside a pistol and the Death Shriek Terrorgheist. Deckhands hold. Deck Gunners shoot. A Vampire Fleet Captain is the caster he is not. A Gunnery Wight minds the guns. Those are the jobs around an admiral whose own magic was cut off.
The chamber
The Academy tells the break this way. While assaulting a hidden chamber, powerful glyphs rebounded his sorcery, shattered the mind into warring personalities, and severed him from the Winds of Magic. The personalities share a goal: plunder Lizardmen sacred places and use Slann artefacts to repair the damage. Piracy and temple raids are the same obsession seen from the sea and from the jungle.
Noctilus has the Galleon’s Graveyard and Phil Kelly’s novel. Aranessa has Sartosa and the living crew. Cylostra has the Lamprey. Harkon has the Lustrian shore and the chamber. Nagash’s Mortarch list can include him in the End Times pack’s campaign. That is a subjugation system on Nagash’s page. It is not a rewrite of the glyphs.
Luthor Harkon: gameplay and availability · More character stories
Sources
- Curse of the Vampire Coast — Total War Academy — academy.totalwar.com
- Curse of the Vampire Coast roster reveal — Total War — totalwar.com
- Immortal Empires DLC Ownership Guide — SEGA — support.sega.com