The premise is almost too neat. A Rebel shuttle goes down on Mustafar in the shadow of Darth Vader's castle. The crew have a long night ahead of them. Somebody starts telling stories.
Why the frame matters
Anthologies usually feel like a filing cabinet — unrelated shorts stapled together because somebody had to fill the pages. Tales from Vader's Castle is built the other way round. Cavan Scott wrote all five issues, so the frame story on Mustafar actually advances week to week while the tales inside it change hands: Derek Charm, Kelley Jones, Chris Fenoglio, Corin Howell and Charles Paul Wilson III each get an issue to themselves.
That is not a gimmick, it is the whole design. Kelley Jones drawing Count Dooku as a Universal-horror aristocrat is a completely different comic from Derek Charm drawing a haunted starship, and putting them one week apart is the point. Francesco Francavilla's covers — orange, black, and very little else — hold the five together on a shelf.
All-ages is not the same as harmless
The thing this line understood, and most children's tie-ins do not, is that young readers like being scared, in the same measured way they like a rollercoaster. A briar witch, a Gorax at night, a Vader who is barely on the page and is worse for it. Nothing here would trouble an adult, and nothing here is condescending either. Cavan Scott said as much about the sequel a year later, describing why he sent Maul to Lotho Minor:
the horror fan in me felt we never saw enough of him
That is the register the whole line runs in — a writer indulging an appetite he had as a reader, on the assumption that the audience shares it.
Where to start
Start here rather than with the sequels; the frame story pays off. If it lands, Return to Vader's Castle (2019) repeats the trick with a stronger artist roster, and Vader's Castle – The Deluxe Library Collection (Dark Horse, 2024) puts all four miniseries and the Free Comic Book Day tie-in in one hardcover.