The deadliest assassin of the DC Universe, Deathstroke, is about to meet the largest audience he’s ever had. Besides an ongoing comic from Christopher Priest, Deathstroke will also be in Ben Affleck’s The Batman (tentative title), but sooner than that, he will return to Arrow for its 100th episode, which airs during the unprecedented four-way crossover beginning November 28. Here’s a reminder that not only does DC’s multiverse allow multiple Deathstrokes to exist, but that TV and movies sharing characters isn’t a new phenomenon.

In the new trailer for “Heroes v Aliens,” Deathstroke appears in a scene that was first teased by actor Stephen Amell on social media. Producer Marc Guggenheim has confirmed there are no flashbacks in the episode, meaning Deathstroke is either a hallucination (as he was in an episode of Season 4) or he’s returned from imprisonment by A.R.G.U.S. to make the Green Arrow’s life hell once again.

If it isn’t obvious by now, the “Arrowverse” — which contains the CW shows Arrow, The Flash, Supergirl, and Legends of Tomorrow, and retroactively Constantine — is separate from the DC Cinematic Universe, which began with Man of Steel and continued this year with Batman v Superman: Dawn of Justice and Suicide Squad.

This isn’t a new phenomenon. Recall in 2006, Smallville starring Tom Welling was midway through its entire run when Brandon Routh played Superman in Superman Returns. In 2014, the supervillain Captain Boomerang was played by Nick E. Tarabay while Jai Courtney played the Aussie mercenary in this year’s Suicide Squad. And lest we forget, Ezra Miller is Barry Allen in Justice League while Grant Gustin has made that role his own in the CW’s The Flash. Both men play Barry with similar youthful charm, but each will invariably be unlike the other.

Warner Bros.’s plans to keep its TV and movie continuities separate has enabled a solid theory that the live-action DC Universe are contained in a multiverse, which mirrors the comic books that also have untold parallel universes with differing and similar characteristics. That explains why we’re going to see a bunch of Deathstrokes very soon. Now it remains to be seen how these Slade Wilsons will get there.

Photos via The CW