With the current version of the game, where the world is frozen in time, having a civ leader leave your map has the same effect as killing him. So your goblins no longer have a leader and they will no longer bring mounts.
That's... unfortunate. I was looking for capturing her and user her for target practice (and then maybe put her head on a spike like the kings of yore, to rattle the siegers).
Then again, I did know that once a leader is killed, they would stop bringing mounts.
It is also a pity that their civ numbers don't matter in fort mode, as 10k goblins just lying in wait for someone to kill them is quite enticing indeed. Oh well, maybe some luck in Adventure mode.
In regards to the actual storyline, I find it interesting, but somehow lacking. Here's the gist of it.
- 4 Demons came, nothing out of the ordinary (except for the fact they just seemed to wait for the ruling demon to kick his boots). They were killed by members of their civ, 2 goblins, 1 human and 1 dwarf, completely unrelated one to another.
- Then things got a little dwarfier. Except that they were killed in duels by challenging demons. They lasted about 1 year each. The demons lasted more time, about 20 years each. To be honest, the demons were the most moral of all the races. They earned their right to rule their civilization by
good honest combat.
- Then, the last demon was murdered by a dwarf. A completely unrelated dwarf was promoted, which after 60 years was murdered by yet another unrelated dwarf. Another random dwarf was promoted, ruled for 35 years, then killed by another dwarf. And so enters Rovod.
None of the murderers have any formal relationship with any of the victims or the new leaders. Which leads me to the following conclusion:
Dwarves in Dark Fortresses are a bunch of mafiosi, sending out unnamed hitdwarves to kill whoever is in charge.
Seeing as how dwarves in that particular fortress reach 500, whereas goblins reach 10k, seems to reason that goblins are just commoners in relation to the dwarves that were adbucted (again, by dwarves). This leads to the conclusion that this breed of "dark dwarves" just "liberates" other dwarves from their lowly plump helmet farming duties and instead invites them to a new empowered life.