The Crowfall site has been updated with a new FAQ about how players will be able to harness the power of fallen warriors that are bound to dying worlds.
Bound to dying worlds, players have a chance to offer thralls a chance to serve the Gods, to be redeemed, in effect. They can be craftsmen or spectral guardians. Their time is limited, however, after which they will be released to eternal rest.
Thralls retain the training and abilities they had in life and can work as vendors, craftsmen, trainers, guardsman, or runecrafters. They come complete with abilities that give them a boost in certain tasks than others.
Players need to beware, however, as thralls are not always willing to remain in service of the Gods and will look for ways to leave. According to the FAQ, the more powerful the thrall, the harder it is to control.
Capturing a thrall will require the use of a soul gem, though the system has yet to be completely revealed as it is still a work in progress.
It's an enTHRALLing read, so be sure to head to the Crowfall site for more information.