Legion director Scott Stewart announced through his Twitter Page that Christopher Plummer and character actor Brad Dourif(Halloween 1 & 2) have joined the cast for his upcoming post-apocalyptic thriller, Priest. Variety also reported yesterday that Californication’s Mädchen Amick will also star.

The trio joins Paul Bettany, Cam Gigandet, Maggie Q, Karl Urban, Stephen Moyer and Lily Collins.

An adaptation of the TokyoPop comic book, Priest is set in a world ravaged by centuries of war between man and vampire. The story follows a warrior priest (Bettany) who turns against the church and enlists the help of a female priestess/vampire hunter(Q) and a sheriff(Gigandet), in order to track down a murderous band of vampires who have kidnapped his sister’s(Amick) daughter. The vampires are lead by Black Hat(Urban), who was once a priest and hunter but now fancies himself a god of vampires.

No word as of yet on what roles Plummer and Dourif will be playing. But I absolutely love both actors. It’ll hopefully reunite Dourif with his Lord of The Rings: Two Towers co-star Karl Urban.

Priest is being prepped for release on August 13, 2010.

So what do you think of the cast for Scott Stewart’s Priest so far?