What’s a superhero without a super-villain? (According to Captain Cold, it means they’d be “out of business.”) Luckily, there are no shortage of bad guys for our favorite heroes to take on–especially in Central and National Cities.

Late last month, TVLine confirmed the return of two of Supergirl’s (Melissa Benoist) former foes: Livewire (Brit Morgan) and Metallo (Frederick Schmidt). What makes these two villains so special is that not only did both of them team up with other villains (Silver Banshee and Metallo 2.0, respectively), but Kara received help in taking on both of the dastardly duos in the form of the Scarlet Speedster (Grant Gustin) and the Man of Steel (Tyler Hoechlin), respectively. Executive producer Ali Adler also revealed that other “fan-favorite” villains will be returning in 2017 (one of those already announced to be Roulette in the midseason premiere).

In more recent news, however, it was announced today at The CW’s Television Critics Association previews that the villain for the two-episode Supergirl/The Flash musical crossover will be none other than the Music Meister, the musical menace made famous by Neil Patrick Harris on Batman: The Brave and the Bold. As to whether or not Harris will reprise the role, here’s what the actor told IGN:

“I’ve heard about it, but that’s as much as it has been. I mean, I did the Music Meister in a recording booth in L.A. […] 15 years ago or something, y’know, and it comes out a year later. […] It was a fun episode, it was a good thing to day. But I’ve heard that Joss [Whedon] is involved in some way, but I don’t know if that’s true or not. … He wears a big zoot suit, from what I remember. The song was fun to sing, so I don’t know; we’ll see.”

Neither Harris nor Whedon are attached to the project as of now but, as we’ve learned from Barry Allen, anything is possible. “We’re certainly huge fans of [Harris],” Andrew Kreisberg said, “and as the casting process proceeds, we’ll see what happens.” CW president Mark Pedowitz added that they’re “very excited” about the crossover as “there’s great musical talent on both shows”.

Finally, the news we’ve all been waiting for since May has officially been released: Black Flash will return..but not only on The Flash. At the end of the Season 2 finale, Barry lured the Time Wraiths out of the Speed Force. Upset at Hunter Zolomon (Teddy Sears) for his manipulation of time, they turned him into the infamous Black Flash and dragged him into the Speed Force. Here’s what Kreisberg had to say about the character:

“He will [be] the classic comic book Grim Reaper aspect. It’s just going to be on multiple shows. He’s a classic character and we have storylines on multiple shows that fit having him return. There’s something so scary about him, even scarier than when he was just a man because now he is the Grim Reaper, he is like the Devil. How do you stop the Devil? It presents an interesting challenge for the heroes of the respective shows in which he appears.”

With the Reverse Flash (Matt Letscher) currently part of the Legion of Doom over on Legends of Tomorrow, it’s not surprising that Black Flash would show up there, but what will be interesting to see is if/how he appears on Arrow or Supergirl. Also, when asked whether Sears will be reprising the role, Kreisberg answered that he’s “not sure” as the actor is “pretty busy” with 24: Legacy. Here’s what Sears told TVGuide about the possibility of his return:

“It would be a lot of fun to drop back into that world. We’ll just have to see if the guys on the other end feel the same way. It sounds like they do, but it’s funny – now I belong to Fox, so there’s lots of people that would have to give a thumbs up. But I really hope so.”

Supergirl returns on January 23rd at 8/7c and The Flash returns the day after also at 8/7c both on The CW. Stay tuned for more news from today’s TCA previews!