Don't watch this show regularly, only contact with its protagonist is on the crossovers. This was an amazing episode! I'm also biased because i'm a Thomas Lennon fan. The inclusion of.. Mxylptlk (not looking it up) and his portrayal was cute, captivating and comedic. The episode is also a mini catch-up through the perspective of Kara and Lena's relationship as the seasons pass. As far as filler episodes of the Arrowverse type i.e. musicals, alternate artistic portrayals or Groundhog day, this one was good.