The latest addition to "DC's Legends of Tomorrow" is Peter Francis James, playing a character new to the show, as reported by ComicBook.com. James will first appear in the "Arrow" crossover episode setting up "Legends of Tomorrow," before continuing to the spinoff series itself.
James' character will be called Dr. Aldus Boardman, who doesn't appear to be based on a character from DC Comics lore and is closely connected to Hawkgirl (Ciara Renee) and Hawkman (Falk Hentschel). Here's the official description: "a Classics professor at St. Roch University, who has devoted his life to researching the story of Chayara (Hawkgirl) and Prince Khufu (Hawkman) and their link to Vandal Savage. Professor Boardman is our team's only hope of finding Vandal and destroying him, so they can return home. But when the Legends learn a secret about Boardman, they insist on making him a part of their journey, only to learn the kind of sacrifice it will take to save the world."
While James is a newcomer to the Arrow-verse, he's got history with both Greg Berlanti-produced shows (he guest starred "The Mysteries of Laura" last year) and live-action DC adaptations (he played Fadhil in 2010's "The Losers").
Expanding the DC-based superhero world of "Arrow" and "The Flash," "DC's Legends of Tomorrow" is slated to debut midseason on The CW.