Fan favorite series flocked to San Diego Comic-Con to dish on upcoming seasons. "Legends of Tomorrow" had a lot to tease about season 4. Last season the Legends battled a time demon which brought back John Constantine (Matt Ryan) to lend a hand. The series has always been flexible with cast changes happening at the end of every season. Season 4 won't be any different. Keiynan Lonsdale (Wally West) was promoted as a series regular during season 3 and was expected to return to season 4, but following the end of season 3, Lonsdale announced his departure from the series.

The actor made it clear that Wally wouldn't be gone forever and he was open to returning to the Arrowverse. After going from a series regular to a recurring role, Arthur Darvill (Rip Hunter) officially departed the series at the end of the season when Rip sacrificed himself so the team could fight Mallus. During the SDCC panel, showrunner Phil Klemmer shot down Citizen Cold and Firestorm returning this season.

Ramona Young and Tom Wilson join the cast

Jes Macallan (Ava), Courtney Ford (Nora Darhk), and Matt Ryan were promoted to series regular status for season 4. The "Legends of Tomorrow" panel revealed the casting of Ramona Young as Alaska Yu who is described as a young girl with a "fantasy novel obsession" and has expertise on "magical creatures," TVLine noted.

Tom Wilson (Biff from "Back to the Future") has been cast as Nate's father who is described as a "charmer" that gives Nate big shoes to fill. The introduction of Hank Heywood will give an inside look into Nate's history.

The season 3 finale saw the departure of Amara, but Maisie Richardson-Sellers is far from gone. Richardson-Sellers will remain a series regular and will be returning as Charlie.

The actress explained to TVLine that her new character is a magical fugitive and described her as a rebel without a cause as well as a trickster. The Legends will eventually come upon her and she'll end up challenging the team. Phil Klemmer teased the return of the beloved (and bizarre) character of Beebo which was seen in season 3 and was a key in defeating Mallus.

The Legends face magical creatures

Jes Macallan teased during the panel that the Time Bureau will be seen and the set has already been built. The actress added the romance between Ava and Sara will continue to be explored. The couple faced a few rocky moments in season 3 as Sara battled her inner demons and Ava made the shocking discovery that she's a clone from the future. In season 4, they will try to domesticate their relationship and find time for each other around their busy schedules. Tala Ashe (Zari) dropped a hint about the Legends attending Woodstock and possibly meeting the Beatles while Courtney Ford shared that Nora is on her own for the first time (without her father or a time demon possessing her) so the season will find her on a path of self-discovery.

The trailer unveiled at Comic-Con revealed several delightful teases for what follows after Constantine found the Legends on the beach with a dragon's head in tow. This season the team will deal with magical creatures that have found their way back into the world and have brought danger with them. The team even get the chance to meet a unicorn. The trailer also teased the return of Gary (Adam Tsekhman) who remains the Legends' biggest fan. Klemmer said during the panel that the lives of the Legends have gotten tranquil so now they'll be forced to turn against their own. He added that he doesn't want cosmetic plot shifts but he does want lasting consequences that affect the DNA of "Legends."

The CW has heavily promoted the epic crossover events between superhero series "Arrow," "Supergirl," "The Flash," and "Legends of Tomorrow." Unfortunately for fans, this year "Legends of Tomorrow" won't be involved in the epic event.

Caity Lotz (Sara) shared with TVLine that "Legends of Tomorrow" isn't the same kind of show as the other three so they stand out and went on to describe the crossovers as crazy. The actress also revealed the difficulty of working with such large casts and trying to do every character justice. That said, the cast remained open to having smaller crossovers with their superhero pals. Fans can expect "Legends of Tomorrow" to return October 9.