Spoilers: The Wargrove, Glamoured Elves, and Coeddil. The forest king's novel is Orion's.

The Wargrove of Woe
Drycha is free with Realm of the Wood Elves, the same pack as Orion and Durthu. The Wargrove of Woe still heals forests and uses the Deeproots. Her Elven troops are Glamoured: weaker, and Expendable. The campaign quest frees Coeddil, an Ancient Treeman held in the Wildwood, as a Legendary Hero rather than a fourth starting lord.
She casts where the spirits are already fighting. Tree Kin hold. Branchwraiths mix magic and melee. Glade Guard can still shoot, under the penalty that comes with a Glamoured regiment. A forest left behind still needs someone on it. The Deeproots are a road, not a reason to abandon the Heathlands around home.
Distrust as a recruitment rule
Orion's page already has the pact and the distrust between Elven warriors and woodland spirits. Durthu is the ancient who helped bind that pact, and his Argwylon campaign can still field the Elven line beside the spirits. Drycha is the lord who makes the distrust the recruitment rule. Glamoured Elves are the rule on her roster.
The Sisters of Twilight fly, shoot, and spend Daith's Favour at the Forge. They require The Twisted and the Twilight. They share the forests and the Deeproots. They do not share Drycha's penalty on elves, and they do not share her quest for Coeddil.
Coeddil's quest, and the king's novel
Coeddil's freedom is a quest on this campaign. He joins as a Legendary Hero once the quest is done. He is not a second Legendary Lord with a start of his own. The Wildwood on the play page is where he is held. The rest of the map is still the player's forest war.
The Vaults of Winter follows Orion through a cursed spring and leaves its traitor unnamed. The seasonal king in that novel is the forest king. Drycha's Wargrove is the free campaign beside his. A restored forest in Immortal Empires is the ritual on the map.
Drycha: gameplay and availability · More character stories
Sources
- SEGA Immortal Empires DLC Ownership Guide — support.sega.com
- Orion: The Vaults of Winter — blacklibrary.com
- The Twisted & The Twilight release announcements — store.steampowered.com