Supergirl Season 2: 8 Easter Eggs & References You Might've Missed In 'The Adventures Of Supergirl'

Season one hinted that J’onn J’onzz had a history with Superman and here we finally learn what happened between them. It turns out that J’onn is responsible for the naming and distribution of Kryptonite. While J’onn intended it to be used to fight the "other Kryptonians out there” (an oblique reference to General Zod), Superman saw it as a threat to his own safety. While this is all original to Supergirl, it does reference the fact that the pair are traditionally colleagues – co-founders of the Justice League, to be precise.

Also, Superman argues to J’onn that the danger of Kryptonite is that “the president herself” could order it to be used on him and Kara. This is a nice set-up for Lynda Carter’s (AKA Wonder Woman) appearance in episode three as a female POTUS.

At one point, Winn refers to J’onn as “Martian Manhunter.” Please correct me if I’m wrong, but I’m pretty certain that this is the first use of the character’s usual sobriquet on Supergirl. If so, it’s quite fitting that it should happen in the episode that also introduces Superman.