Spoilers: The exile. No campaign ending.

Who he is in Total War
Khatep leads the Exiles of Nehek, one of the four lords in Rise of the Tomb Kings. The Academy calls the start a hard one. He is banished far from the other Tomb Kings, with stronger enemies nearby, and he begins with a Hierotitan and Carrions. The Exiles can live in the mountains. They gain canopic jars each turn without leaning on a character trait, and they have diplomatic trouble with the Dark Elves beside them. A movement benefit applies to their armies.
Lore of Nehekhara is his spell lore. Dynasty research, replenishment, and army movement are the FAQ’s faction shape, with more Liche Priests recruited at a higher rank. Constructs still need a Necrotect’s care.
The priest who woke the king
The FAQ is the short canon used for the character. Khatep is head of the Hierophantic Council, the oldest and wisest of the Liche Priests, and the first of them to deny death. He awoke Settra to unlife after Nagash’s Great Ritual levelled Nehekhara. Settra’s distrust of the Mortuary Cult then drove the exile. Khatep roams the Land of the Dead, helping other Tomb Kings where he can, and looking for a way back into Settra’s regard.
The Academy tells the same banishment as a campaign condition. He can return when the Mortuary Cult fulfils the promise to restore Nehekhara’s golden age. That condition is the exile’s story. It is not a victory button with a published result. Settra’s own page carries the king’s side: order restored, the cult’s answer to death rejected, Khatep sent away.
Settra, Khalida, and Arkhan
Khalida rules Lybaras and hates vampires, with Neferata named in the FAQ as the cousin who slew her. Arkhan serves Nagash and can field Vampire Counts units. Khatep serves the cult Settra no longer trusts. Three loyalties sit in one DLC. Confederating them in a sandbox is a player’s map, not a reunion the FAQ narrates.
The Mortuary Cult’s promise, the Great Ritual, and the exile are the story the FAQ and the Academy give him. Play the Exiles from the lord page. Read Settra and Nagash when the ritual itself is the subject.
Grand Hierophant Khatep: gameplay and availability · More character stories
Sources
- Rise of the Tomb Kings FAQ — Total War — totalwar.com
- Tomb Kings: Legendary Lords — Total War Academy — academy.totalwar.com
- SEGA Immortal Empires DLC Ownership Guide — support.sega.com