This is the 4th episode according to Netflix.
Kara and Alex’s mom shows up for a visit. Meanwhile, an ex-CatCo employee gets turned into a supervillain with the ability to turn into electricity.
Supergirl’s first real supervillain, and you know what, it works pretty well. Giving Kara a real challenge and someone worthy of her powers and an actual threat for a city with benevolent Super-people in them.
Also, much less relationship drama in this one, also a benefit to the show. And Cat Grant plays a prominent role in this one without feeling like another thorn in Kara’s side and constantly trying to put her down. Characters are more likable when they’re free to be actual characters instead of falling into archetypes or easily accessible tropes.
+10: Best episode so far, real characters and a real supervillain