Max Adler Joins ‘The Flash’ as Fire Starting Villain
Even though Barry is currently in prison, the bad guys never stop coming to Central City. Grant Gustin will be joined by another Glee co-star when Max Adler guests on The Flash as fire starter Jaco Birch.
Jaco is said to be a “an obsessive music fanatic who worships at the altar of classic heavy metal. Birch is a roadie for all the contemporary metal bands you’ve never heard of…and there’s one other thing: he loves to set things on fire.”

Grant Gustin as Sebastian and Max Adler as Karofsky in the Glee episode On My Way.
It doesn’t seem as though Jaco is based on a particular comic book rogue, however, the Arrowverse is known for taking liberties with its villains. So, it’s possible Jaco’s comic origins will become more evident when the episode airs in March.
Along with Gustin, the Arrowverse has featured many Glee stars including Supergirl’s Melissa Benoist and Darren Criss as the Music Meister in the musical crossover.
The Flash airs Tuesdays at 8 pm on The CW.
Source: Flash TV News