Warning! The following contains spoilers for the Supergirl episode "Mxy In The Middle." Read at your own risk!
Supergirl brought back fan-favorite Mr. Mxyzptlk, or Mxy, in its latest episode as Kara made a last-ditch attempt to try and thwart Nyxly before she did further damage to National City. Mxy arrived on the scene, and fans learned that he and Nyxly had a complicated history, and the end of the episode left Mxy's fate very much in question.
After a song that detailed their storied history, Mxy went about trying to thwart Nyxly, and it came at a great cost. Nyxly trapped Mxy in a crystal, but not before he was able to slap a power dampener on her wrist. Mxy vanished, and it wasn't entirely clear to even the Supergirl characters whether he was gone or merely trapped inside the crystal. Thomas Lennon spoke to The Wrap about Mxy's moment in the episode and admitted he's not quite sure what happened after the crystal incident.
I swear, it seems like I’m being cagey. But I actually don’t know what happens next in the storyline.
If Thomas Lennon isn't aware of what happened to Mxy, and genuinely isn't being cagey, then fans will have to rely on Supergirl's final episodes for the answer. The season has wrapped, and Lennon referred to the appearance as his "swan song", so that would presumably mean that's the last we'll see of him and that he truly doesn't know whether his character's survival was ensured one way or another. In the episode, Nia suggested it's possible Mxy was merely trapped from within the crystal, which could give hope to Supergirl fans that he made it through.
The truth of the matter is, though, even if Mxy survived, Supergirl is headed to an end. Thomas Lennon's version could still re-appear elsewhere in another show in the Arrowverse for sure, though one would imagine that his escape from the crystal in Supergirl would need to be explained. Then again, it's not like the Arrowverse has an absolutely stellar record of explaining continuity changes across its multiple shows, so it may not be that big of a hurdle for another show to figure out should they want Lennon in their world as Mxy.
If Supergirl will be the final appearance of Thomas Lennon's Mxy, at least it ended in a tale of redemption for the mischievous DC character who has had an up and down history with Supergirl in the series. That's a decent ending, but also a shame given how goofy and fun he made the portrayal. Unfortunately, this wouldn't be the first time the Arrowverse has lost a treasured actor. There will be others gained, and sadly, probably more lost in the years to come.
Supergirl airs on The CW Tuesdays at 9:00 p.m. ET. Speaking of Supergirl characters we'd rather not see leave entirely after this show ends, read up on the one actor who'd love to stick around, if given the opportunity, here.