For its second season, DC's Legends of Tomorrow is undergoing a major cast overhaul.

When Legends returns on Thursday, Oct. 13 at 8/7c, Hawkgirl and Hawkman are long-gone, but they'll soon be replaced by two new heroes, Nathan Heywood and Amaya Jiwe, both of whom are related to other superheroes in the Arrow-verse. (Talk about good genes, amirite?)

As if that wasn't enough, the CW drama is also introducing an entirely new team of superheroes, the Justice Society of America, which includes Hourman, Stargirl and a handful of other 1940s do-gooders.

And it's a good thing the Legends are meeting the JSA, because they're going to need all the help they can get when they're forced to come up against the Legion of Doom, a team of supervillians that includes Legends' own Captain Cold (Wentworth Miller).

If you're starting to get overwhelmed, sit down, take a breath and relax, because we've put together a handy primer on all the new heroes and villains heading to Legends of Tomorrow Season 2.

Maisie Richardson-Sellers and Nick ZanoMaisie Richardson-Sellers and Nick Zano

The Legends

Nathan Heywood/Citizen Steel (Nick Zano): The first new recruit to join the Waverider team, Nathan is a historian who sets out to help save the Legends in the season premiere. But soon enough, Nate discovers his own powers and will be forced to become a hero himself.

In the comics, Nathan is also known as Citizen Steel, a former football star who gained super-human strength and grew metal body parts after being attacked by metahuman Neo-Nazis. Nathan Heywood also has close ties to the Justice Society of America since his grandfather, Commander Steel, was a member.

Amaya Jiwe/Vixen (Maisie Richardson-Sellers): Amaya shares the Vixen mantle with her granddaughter Mari McCabe, who was portrayed by Megalyn Echikunwoke on Arrow. And like Mari, Amaya will magically be able to access the abilities of animals, thanks to the Tantu Tomen.

The Legends will be introduced to Amaya when they travel to the '40s and meet the Justice Society of America in Episode 2 (airing Oct. 20). After this encounter, Vixen will leave behind her JSA team and board the Waverider to join the Legends on their mission to protect time.

Sarah Grey, Kwesi Ameyaw, Patrick J. Adams, Dan Payne, Maisie Richardson-Sellers and Matthew MacCaullSarah Grey, Kwesi Ameyaw, Patrick J. Adams, Dan Payne, Maisie Richardson-Sellers and Matthew MacCaull

Justice Society of America

Rex Tyler/Hourman (Patrick J. Adams): Legends fans briefly met Rex Tyler in the Season 1 finale when he warned the Legends not to get back on their ship. This season will explore the reasons behind Rex's ominous warnings and go deeper into the Justice Society of America, of which Rex is a founding member.

Viewers can also expect to see Hourman in action this season, since he didn't really do much more than scare the pants off the Legends in his first appearance. In the comics, Hourman had super-strength and speed as a result of taking the vitamin Miraclo. The twist? Hourman would only have these abilities for an hour after ingesting Miraclo.

The CW's four-way superhero crossover has found its big bad

Henry Heywood/Commander Steel (Matthew MacCaull): Nate Heywood's grandfather and the original Commander Steel in the comics, Henry was injured after he enlisted in the Marines. When a doctor performed surgery on Henry, he enhanced his body with steel, giving him superhuman strength, speed and durability.

Todd Rice/Obsidian (Dan Payne and Lance Henriksen): Possessing some of the coolest superpowers ever, Todd - aka Obsidian - can merge with his own shadow and possess the shadows of others. When he's in shadow form, Obsidian gains super strength, the ability to pass through solid objects and fly. In the comics, he also has a small degree of telepathic powers, which can force a person to see the evil side of their own soul.

But Todd isn't your typical hero. Todd struggled with his mental health in the comics and at one point was even a full-fledged villain. He is also the son of Green Lantern Alan Scott and eventually came out as gay — two things Henrikson confirmed will be included in Legends this year.

The CW show is poised to cover a good deal of Todd's arc this season, since they cast two actors for the role: Payne, to portray a young Todd in the '40s, and Henrikson, to play the older version.

Courtney Whitemore/Stargirl (Sarah Grey): A rare superhero who doesn't naturally possess any powers, Courtney gets all her abilities from a magical staff and belt which enable her to fly and manipulate energy.

In the comics, Courtney became a superhero after finding the original Star-Spangled Kid's cosmic belt in her stepfather Pat Dugan's belongings. As angsty teenagers are wont to do, Courtney wore the costume as a way to annoy her stepfather who used to be Stripesy, the only adult sidekick to the teen hero ever. But soon, Courtney and Pat were operating as a new superhero duo until Courtney went off on her own and took on the moniker Stargirl.

Dr. Mid-Nite (Kwesi Ameyaw): Before there was Daredevil, there was Dr. Mid-Nite, the world's first blind vigilante - well, at least during the daytime. It turns out that while Dr. Mid-Nite can't see in daylight, he can see perfectly well in the dark.

As of now, it's unclear which version of Dr. Mid-Nite Legends is going with. There have been three different men to use the name in the comics so far: Charles McNider, Beth Chapel and Pieter Anton Cross. The one thing all three have in common is that all their iterations of Dr. Mid-Nite have also been physicians, so we expect that aspect of the character to remain intact.

John Barrowman, Matt Letscher and Neal McDonoughJohn Barrowman, Matt Letscher and Neal McDonough

Legion of Doom

Malcolm Merlyn/The Dark Archer (John Barrowman): Arrow fans will be extremely familiar with the Dark Archer, who is the archenemy of Oliver Queen (Stephen Amell) and the biological father of Thea Queen (Willa Holland). Malcolm was also briefly the leader of the League of Assassins before Nyssa al Ghul (Katrina Law) took over and disbanded the organization.

He's one of those villains who often teams up with the heroes to defeat a common enemy and sometimes even has genuinely good intentions. But Malcolm can't resist his own evil temptations and he always reverts back to being a bad guy.

Eobard Thawne/Reverse-Flash (Matt Letscher): Eobard is a speedster from the future and a descendant of Eddie Thawne (Rick Cosnett). Reverse-Flash was the main villain of The Flash's first season, but was killed when Eddie sacrificed himself to stop Eobard from ever being born. Yet despite the fact that Eobard no longer exists, time remnants of him were preserved in the Speed Force, allowing him to continue to appear.

Damien Darhk (Neal McDonough): Darhk was a former member of the League of Assassins and the leader of H.I.V.E. until Oliver Queen killed him in Arrow's fourth-season finale. He harnessed his dark magic powers from the Khushu Idol, which gave him accelerated healing, super-strength, telekinesis, teleportation and the ability to siphon the life-force from people.

Darhk also happens to be the person who murdered Sara's (Caity Lotz) sister Laurel Lance (Katie Cassidy). And since Sara has never been one to put much stock in the rules, this season of Legends will find her determined to track down Darhk and kill him before he can ever harm Laurel. Because who cares about preserving the timeline when you can save your sister's life? Someone who has clearly never watched the Ashton Kutcher classic, The Butterfly Effect, that's who.

Are you excited for Legends of Tomorrow to return? Season 2 premieres Thursday at 8/7c on the CW.

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