The “Flash/Supergirl” musical crossover episode has officially cast Darren Criss as the Music Meister — making this the biggest “Glee” reunion on record.

“With our Flash and our Supergirl being ‘Glee’ alums, how could we not have them go up against another ‘Glee’ favorite like Darren Criss?” executive producer Andrew Kreisberg told TVLine. “We have been blown away by his talent over the years, and we can’t wait to see what he brings to the Music Meister.”

Most of us remember Criss as Kurt’s (Chris Colfer) long-time love on “Glee,” and some of us even remember how his college musical based on Harry Potter (“A Very Potter Musical”) took the Internet by storm in 2009.

RELATED: Malcolm Merlyn, Martin Stein & more to appear in ‘The Flash’ & ‘Supergirl’ musical crossover

Now, Criss is sinking his teeth into the superhero genre — and we’re more pumped for this episode than ever. We’ve never seen Criss take on a truly nefarious role before, but we’ve got faith that he can make this campy villain one of the best (and likely most absurd) “The Flash” has ever seen. And when you factor in his charm and show-stopping musical abilities, Criss makes the perfect fit for a baddie who warps Barry (Grant Gustin) and Kara’s (Melissa Benoist) world into one big stage production.

Obviously, we’re bummed Neil Patrick Harris won’t be making a stop in Central City — to reprise his role as the Music Meister from “Batman: The Brave and the Bold” — but there’s no more perfect alternative than Criss.

We can’t wait to see how he’ll sing, dance and stir up trouble for Barry on “The Flash.” Joining Criss in his musical endeavors will be Cisco (Carlos Valdes), Joe (Jesse L. Martin), Martin Stein (Victor Garber), Malcolm Merlyn (John Barrowman) and Winn (Jeremy Jordan).

“Supergirl” and “The Flash” air Mondays and Tuesdays respectively at 8 p.m. ET/PT on The CW.

Posted by:Lindsay MacDonald

Lindsay MacDonald is a Los Angeles based entertainment reporter with an affinity for CW superheroes. She graduated from Pepperdine University with a major in Media Studies and a borderline unhealthy obsession with TV in 2012. She would much rather spend the day binge-watching ‘The Flash’ or sorting ‘Game of Thrones’ characters into Hogwarts houses than venturing outdoors. TV words to live by: “Never ignore coincidence. Unless, of course, you’re busy. In which case, always ignore coincidence.”