The Stygeon prison known as the Spire was the same secret facility where Darth Maul was held captive in the comics series Darth Maul: Son of Dathomir. The environment was developed for an episode of Star Wars: The Clone Wars that was never completed.
The last time we saw Luminara Unduli she was commanding clone troopers on the beaches of Kashyyyk. The circumstances surrounding her death have not been depicted (an animatic from Episode III available on the Blu-ray set has her being gunned down by a circle of clones), but her bones have been put to evil use by the Inquisitor.
The creatures that are attracted to the Phantom are called tibidees. This name stems from the fact that, for a time, the creatures were labeled “TBD” by the production team, meaning their names were still “to be determined.”
The Inquisitor identifies Kanan’s Master as Depa Billaba. Depa can be seen on the Jedi Council in Episodes I and II. She will be seen alongside her teenaged Padawan in the forthcoming flashback comic series, Star Wars: Kanan -- The Last Padawan, written by Greg Weisman with art by Pepe Larraz.
The voice of Gall Trayvis, Senator-in-Exile is provided by Brent Spiner, who is perhaps best known for his role as the android Lieutenant Commander Data on Star Trek: The Next Generation.
