There could be characters like Hera Syndulla. She is often associated with Kanan and might play an important role in the graphic novel. Maybe Ezra Bridger could also be in it as he has a connection to Kanan in the Star Wars lore.
Whether the Kanan comics are canon is a matter of debate. Some aspects might align perfectly with established lore, but there could be elements that don't quite fit. It's not a straightforward yes or no answer.
A possible character for the High Inquisitor could be a long - lost relative of Dolores Umbridge. They might share her strict and often cruel approach to discipline. This character could have been in hiding for years, secretly observing Hogwarts from afar and waiting for the right moment to impose their own version of order.
Well, it's a bit complicated. The determination of whether the Kanan comics are canon often depends on the decisions of the creators and the broader narrative context. Sometimes new developments or retcons can influence this status.