I thought about doing a post-Boatmurdered (Koganusan, I think it's called in dorf-nonsense).
Imagine a new settling of the Boatmurdered we have come to love and fear. Dwarf resettling the horrid chambers and halls of boatmurdered, trying to re-establish the glory of the early fortress. You know, the twelve seconds before everything turned into ELEPHANTS AND MAGMA.
Of course, the sheer spirit of Boatmurdered seeps out from the horrible engravings, and the screams of Sankis, the Lich Engraver, begin to emanate from caved-in corridors. After a few years, the new Boatmurdered is on edge, fearful and wrought with the guilt of what they may have resurrected.
The bright dreams of resurrecting one of the most famed fortresses in dwarven history has turned into a lovecraftian nightmare of screams, paranoia and ghost elephants trampling through the meeting halls, echoes of unholy trumpeting mixing with the insane whispers of the Master of the Place: The Unholy Sankis.
If done as RPG, the players could be representatives of the mountainhome, who arive to liase with the inhabitants of Koganusan. Expect to not live. And to hate Elephants.
Good spirits could be some of the other rulers of the first boatmurdered, but Sankis should either be the BBEG or at least someone the players can align with in order to flood the fortress with lava and release him from his eternal torment.
A torment that mostly consists of engraving images of his own failure.
An added NPC could be a mysterious dwarf female, who tuns out to be the last survivor of the first boatmurdered.