Yet another Glee star is joining the Supergirl/Flash musical crossover episode

The scheduled Supergirl and The Flash musical crossover episode just got even better.

Melissa Benoist, who plays Supergirl, and Grant Gustin, who plays The Flash, both famously hit the big time as singing schoolkids on Glee. It was one of the reasons that fans begged the CW for a musical crossover episode ASAP, after all.

We thought the prospect of Marley and Sebastian singing again would be enough, but now it’s gotten even better.

Darren Criss has been cast in the role of the episode’s baddie – the Music Meister – for the episode.

Series creator Andrew Kreisberg told TVLine: “With our Flash and our Supergirl being Glee alums, how could we not have them go up against another Glee favourite like Darren Criss?”

“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.”

Darren famously played series regular Blaine on Glee, the character whom Gustin’s Sebastian spent the majority of his time pursuing relentlessly. There was a little bit of bad blood between them, although not as much as that between Sebastian and Blaine’s boyfriend Kurt.

Blaine and Marley didn’t clash quite so much, as both were members of the New Directions in the show’s fourth season. Both characters had a habit of belting out the big numbers, however, so we’re expecting something special.