Spoilers: Death Nights, the Blood Voyage, and the Queen and the Crone pairing.

Har Ganeth and the Death Night
Hellebron requires The Queen and the Crone. Warhammer II is a separate purchase. The February 2023 FAQ lists her on that pack's Dark Elf row, with Alarielle opposite her for the High Elves. Har Ganeth spends slaves on Death Nights, and the lift fades. The Blood Voyage is the army tied to that ritual. She leads Witch Elves, Har Ganeth Executioners, and Sisters of Slaughter in melee. A Sorceress covers the magic.
Executioners want a target the spears have already held. Sisters of Slaughter want a fight they can stay in. Witch Elves want to arrive while that line is still standing. When the Death Night has faded, the same regiments still have to win the battle. Dreadspears and Black Ark Corsairs remain the infantry around her.
The queen and the crone
Alarielle's Avelorn watches hostile occupation of the Elven homeland and the wider presence of Chaos. Hellebron's Har Ganeth watches the ritual calendar and the slave stock that feeds it. The pack title is the game's pairing. It puts a High Elf queen and a Dark Elf hag queen on sale together. Their campaigns stay separate.
Morathi is already on the Warhammer II row, leading the Cult of Pleasure. The play page places Hellebron's rivalry with Morathi in the Hag Queens' struggle for power. Lokhir Fellheart and Rakarth can unlock from this same Dark Elf purchase as Free-LC. Their campaigns are the Blessed Dread and the Thousand Maws.
A ritual army, and someone else's flight
A Death Night that empties the slaves is a crisis on this campaign. The Blood Voyage is Hellebron's own army for that crisis. It is a map decision: when to spend the stock, and which border can stand the voyage.
Bane of Malekith puts Tyrion and the Everqueen on the run in Avelorn, with druchii pursuers, and then on Finuval Plain under Malekith. That flight belongs to the twins' third novel. Hellebron's voyage is the Har Ganeth campaign. Clearing Ulthuan in Immortal Empires is the player's war.
Crone Hellebron: gameplay and availability · More character stories
Sources
- Immortal Empires FAQ, February 2023 — totalwar.com
- SEGA Immortal Empires DLC Ownership Guide — support.sega.com
- Bane of Malekith — blacklibrary.com