In the DC Comics, Rip Roar was an Apokaliptian and an enemy of the Young Justice team with powers coming from his New Gods physiology.
This is one of only a handful of episodes to explicitly indicate that National City is located on the Pacific Coast. By coincidence, there actually is a National City located in California, just south of San Diego.
The title shares the same name as Dangerous Liaisons (2017), which in turn was named after the novel "Les Liaisons Dangereuses."
Rip Roar has two metal arms, not unlike Doctor Octopus.
Near the beginning, Kara is talking to William about his investigation, tying to get involved. All the while, they both are customizing their coffees (Kara adds A LOT of sugar to hers). Suddenly, William walks out, and Kara follows him, still trying to convince him. She left her sugary coffee behind, and never goes back to fetch it.