In the DC comics, Psycho-Pirate is a supervillain who wears a Medusa Mask that can manipulate the emotions of others. His first appearance in the comics was Showcase #56. Hayden played a pivotal role during the Crisis in Infinite Earths, in which he was granted part of the Anti-Monitor's power, allowing him multiversal and temporal awareness. This became the character's most defining feature, allowing him to see various "forgotten" variations of timelines and universes in DC's omniverse. Hayden was originally planned to appear in the Crisis on Infinite Earths crossover, but there was not time for another character.
Sue Dearbon learned to dance at the DeMatteis Dance School, referencing J.M. DeMatteis, a prolific comic book writer whose stories focus on psychology.
One of H.I.V.E.'s crates (marked "G6:5") from Arrow (2012) Season 4 can be seen amongst the Starchives' inventory in this episode.
Roger Hayden is finally referred to by his moniker of "Psycho-Pirate" (despite him not actually appearing here), but the mask isn't referred to as the Medusa Mask like it is in the comics.
Kristen Kramer's past is being uncovered by Joe, which implicates Kramer is either working for foreign anti-meta bigots, trying to suppress American metas, possibly being a double agent for Markovia after Gravedigger failed.