How Did Ventress Die in Dark Disciple?

But the last time we actually encountered Ventress chronologically speaking was in the aforementioned Dark Disciple. Written as an adaptation of a storyline from unused Clone Wars scripts—after the show was canceled shortly after Disney’s acquisition of Lucasfilm—the book sees Jedi Master Quinlan Vos go undercover as part of a secret mission ordained by the Jedi Council to assassinate Count Dooku and bring an end to the Clone War.
Tasked at Yoda’s suggestion with partnering with Ventress given her own conflict and history with Dooku, Vos teams up with her initially as a fellow hunter, before slowly revealing more and more of his history as they get closer and closer to taking on Dooku. The two eventually develop a romantic connection—however, it’s tragically cut short when, after engaging Dooku on the planet Christophsis, Ventress seemingly sacrifices herself to save Quinlan—taking the brunt of a blast of Force lightning Dooku intended to kill Vos with—and redeem him from his increasing dark urges, having pushed himself further and further to the Dark Side in his attempts to bring Dooku and his master down. After the failed attempt to kill Dooku, Ventress’ body was taken back to her homeworld of Dathomir by Vos and Obi-Wan Kenobi, where they laid her to rest in a pool suffused with the magicks and spirits of the Nightsisters.