How do ascians come into existence?

[TinyRedLeaf]

The black-masked underlings achieve immortality much like the Sahagin elder, retreating from one corporeal vessel and fleeing into another. However, unlike the red-masked overlords, they seem to lack the strength required to force themselves into a living vessel, only the the nearby dead. They also seem to lack crystals of Darkness, and thus they cannot retreat to a place between worlds where their "soul orbs" will be safe.

This may be a blooper, or something else altogether, but I'm very certain that when the budding WoL and Y'shtola defeated a black-mask in the Limsa Lominsan storyline, it left behind a dark crystal that then went *poof* once the WoL noticed it.

So, I think it may be the case that the lesser Ascians do have crystals, but lack the strength to escape into the rift once their mortal host bodies are destroyed.