CAUSE OF EXTINCTION: Genetic Deterioration.

The Skeksis were a species of xenophobic monotremes related to the griffins. Records of them portray them as a race of stuck-up, narcissistic, backstabbing, cowardly, gluttonous, paranoid idiots... who had access to dark, crystal-based magic able to trap souls and life essence, furthering their goal of "living forever"

their mythology points to a demon as the cause of this, saying their ancestors fled some (undescribed) cataclysm, hiding underground. there they found a bound demon (according to the texts), who agreed to share the secret of immortality in return for its freedom. the griffins leapt at the chance. However, once freed, the demon vaguely told them "the Key is the Crystal", and vanished.

The proto-Skeksis began working with the crystals in the caves, using dark, forbidden magic that warped and twisted their bodies, turning them into the Skeksis.

Skeksis society was ruled by a single Emperor, the SkekSo. below him were nine other classes:

the SkekSil (Chamberlain)

the SkekUng ("General")

the SkekZok (High Priest)

the SkekTek (Head Scientist)

the SkekAyuk (Head Cook)

the SkekNa (Slave-Master)

the SkekEkt (Architect)

the SkekOk (Historian)

and the SkekShod (Treasurer)

Below these were the apprentices, the Sil, Ung, Zok, Tek, Ayuk, Na, Ekt, Ok, and Shod.

Below these were the warriors, who were not Skeksis, and below them, the slaves.

The Skeksis valued power above all else, but saw it purely as dominating others.

When the emperor died, the throne was "up for grabs", with Skeksis rallying support from their peers behind them. In cases where two had an equal amount of support, they did a ritual called Haakskeekah, or "Trial by Stone", where they whacked big rock with giant swords. The Skeksis who is able to hack off the biggest chunk of the stone is declared the winner, and the loser is forced to forfeit his position in the Skeksis court.

Along with "Trial by Stone", disputes could also be settled with "Trial by Fire". The contenders would convene to the ceremonial Fire Chamber and stand, facing each other, upon two heated slabs. Both contenders would then be handed rocks, with the winner being the one to hold the most without dropping them or falling.

The Skeksis (supposedly) died out due to obsession with keeping bloodlines pure. this led to inbreeding, which led to eventual sterility.

However, they kept well-maintained records of their experiments with crystals...

Perfect! Now I have some new ideas to think about, and now I have to get chapter three done soon :D

3183173 the Dark Crystal was an interesting movie, and I just had to add these guys!

3183225 Well very glad that you did. :D

3183228 However, the whole "trial by stone" thing just shows you how stupid they were.

"I want to be Emperor!"

"I want to be Emperor!"

"I have a giant Sword!"

"So do I!"

"Let's whack a giant rock with them! Trial by Stone!"

"...wait, we have giant swords, couldn't we just..."

"TRIAL BY STONE!!!"

3183246 A swollen head so oft' houses a meagre mind.

5958799 https://www.fimfiction.net/group/199698/the-known-world/thread/107496/races-garthim

3183246
Actually there was a sense of pragmatism to having the Trial by Stone.