Supernova

Supernova is the main antagonist in the Rick & Morty episode "Vindicators 3: The Return of Worldender". She appears as a member of the Vindicators who is presumably a famous heroine and a high ranking member in her flawless team however over the course of the episode she slowly shows her true colours to the point of attempting to murder Rick and Morty.

She was voiced by Gilian Jacobs.

Past
In her past she was married to another member of the group known as Alan Rails but ended up cheating on him with a colony of ants who she mutated into a being known as Million Ants who became another member of the team, she and the vindicators also went on a previous adventure with Rick and Morty but didn't invite them for the next adventure since they disliked Rick.

Vindicators 3: The Return of Worldender
The vindicators called Rick and Morty for assistance due to them needing Rick's assistance. During the briefing Rick constantly made jokes and remarks to other members of the team much to Supernova's annoyance. She next appeared whilst going on a mission with the team to destroy their arch nemesis Worldender however a drunken Rick already defeated him the previous night and invented an over complex Saw like trap game. Two members of the team die leaving her, Alan, Rick, Morty and Million Ants. After an argument during which Supernova admits that she and Million Ants had a child and kills Alan. She restrains Rick and Morty. After the final challenge she finally snaps and attempts to murder Rick and Morty, Million Ants attempts to calm her and ends up moving her however she ends up brutally murdering him and once again attempts to kill them again before an elevator leads them up to a party where a pop artist is playing. Supernova pretends to dance to the music and slips away, Morty points this out to Rick however he doesn't care and lets her go free. She is likely to return in a later episode.

Trivia

 * She appears to be a parody of Starfire from DC Comics.