Welcome back to The Hollywood Reporter's weekly DC TV Watch, a rundown of all things DC Comics on the small screen. Every Saturday, we round up the major twists, epic fights, new mysteries and anything else that goes down on The CW's Arrow, The Flash, Legends of Tomorrow, Supergirl and Black Lightning, and Fox's Gotham. There have been a lot of news, castings and announcements all summer long about the new seasons premiering this fall, so this week we're rounding up everything there is to know about Legends of Tomorrow season four ...

Magic and mysticism and demons, oh my! | Last season, the Legends finally earned their vacation in Aruba. They defeated the demon Mallus and took their much needed break on the beach for some surf, sand and relaxation ... and beer for Rory (Dominic Purcell). But what they didn't realize was that by letting Mallus out of his time prison in order to defeat him, they inadvertently left a door open for other monsters to escape. Thankfully, they've got John Constantine (Matt Ryan) as their ally, who shows up and breaks the news to them in Aruba, bearing a severed monster head to boot. This signals a major shift for Legends of Tomorrow in season four, as the misfit superhero group will have to deal with more magic and mysticism on a weekly basis. And to that end, Ryan has been upped to series regular as Constantine, who will take up a more permanent residence on the Waverider as he helps the Legends deal with the monsters-of-the-week. It's exactly what fans have been waiting for since NBC canceled Ryan's Constantine series after only one season, and now he's finally on The CW for good where he belongs.

Not so fast | But as the Waverider gains one superhero, it loses another as the series' revolving door just keeps on turning. Keiynan Lonsdale is no longer a series regular as Wally West/Kid Flash. Lonsdale will appear in The Flash season five premiere, but after that, it's anyone's guess as to when or where he'll show up in the Arrow-verse. The actor is taking a break from the network's superhero series for personal reasons, but that doesn't mean he's gone for good. He just won't be around this season, according to executive producer Phil Klemmer. But executive producer Keto Shimizu promises, "There is always next season!" With the Waverider down one speedster, that levels the playing field a bit more as the series won't have to deal with the "Superman problem" of having its hero be too powerful, so much so that writers constantly have to figure out a way to incapacitate the character or his powers to make it a fair fight. But losing Wally's earnest optimism and joy will definitely be noticed.

New name, same face | When Amaya (Maisie Richardson-Sellers) left the Legends to return to her home in Zambesi in the season three finale, many fans wondered if this would be the last of the actor on the series. However, at Comic-Con it was revealed that Richardson-Sellers is still a series regular for season four — and she'll be stepping in to an all-new role. Richardson-Sellers herself revealed that her new character, Charlie, is one of the "magical fugitives who slips through" the door that the Legends opened in the time prison. Described as "a rebel without a cause, a trickster on her own mission," Charlie shakes up the dynamics on the Waverider as the Legends attempt to figure out if she's friend or foe. The Arrow-verse is no stranger to introducing new characters for the actors to take on, and this is the latest instance of keeping a fan favorite around past his/her original character's expiration date.

Dad drama | With Amaya's exit, Nate (Nick Zano) is already going to be dealing with some emotional drama. So Legends figured why not up the ante and give him some major family trouble on top of that with the introduction of his estranged father, Hank Heywood (Tom Wilson). With a lifetime in the military and Department of Defense, Hank is part of a long line of Heywoods to serve the country. Charming and charismatic, he’s left big shoes for Nate to fill, and the Heywood men have an extremely strained relationship because of it. And apparently Nate hasn't told his dad that he's a Legend. How his father will react to finding out his son is following in the footsteps of his father remains to be seen, but it's probably not going to go over well.

The newest recruit | Ramona Young (Blockers, Santa Clarita Diet) is joining the cast in the series regular role of Alaska Yu this season. Described as a typical twentysomething easily swept up by romantic notions and fantasy novels, she's a walking encyclopedia on the kind of monsters that the Legends will face this season after opening that door to the time prison which previously kept Mallus locked up. In the company of the Legends, Alaska soon learns to get her head out of the clouds and become a kickass superhero.

Hot and heavy | With a glimpse of Sara (Caity Lotz) and Ava (Jes MaCallan) naked in bed looking extremely happy together in the season four trailer, it's clear that Legends of Tomorrow is leaning in to romance this year. Klemmer promises that Sara and Ava's relationship is only getting better and better from here on out. As their relationship gets deeper and more meaningful, that will allow Legends of Tomorrow to expand the world of the Time Bureau even more thanks to Ava's work life, which is how Alaska will be introduced. In fact, now that history has been infected with these time "fugitives" — magical creatures from myths, fairy tales and legends – the organization is distrustful of and ill-equipped to deal with magic, so it's actually forced to team up with the Legends and Constantine to get history back on track.

On their own | In a surprise twist of fate, this year's big Arrow-verse crossover will be down one show: Legends of Tomorrow. The Legends will not be participating in the Batwoman crossover later this fall for no reason other than there are just too many characters to service across all four shows and Legends' tone is just too different compared to Arrow, The Flash and Supergirl. That doesn't mean they won't crossover with any of the other shows in the future; they just won't be seen in this specific event.

Legends of Tomorrow returns for season four Monday, Oct. 22, on The CW.