At the beginning of the episode, Marley says that dressing up as a superhero and wearing a full-body spandex suit is not her style. Actress Melissa Benoist (who plays Marley) left "Glee" after season 5 after being cast as the title character in the new live-action TV series "Supergirl" (2015).
All three actors, Melissa Benoist, Darren Criss, and Grant Gustin, came back and filmed together in the episode "Duet" on the CW's The Flash starring Grant.
Nolan Gerard Funk (Hunter) and Grant Gustin (Sebastian) both go on to guest star on the series Arrow (2012).
Grant Gustin (Sebastian) would later go on to play Barry Allen/The Flash (2014-).
This is the first show that the character Will Schuester does not appear in.