Warning! The following contains spoilers for the Supergirl Season 6 premiere, "Rebirth." Read at your own risk!
Supergirl returned to The CW for its final season, but there was barely any time for the heroes to take a breath as they had to work to thwart a massive plot by, who else, Lex Luthor. He had a satellite system poised to kill every person he hadn't brainwashed in the world, and of course, a plan to destroy Supergirl herself once and for all.
The episode was a masterclass in why Jon Cryer's Lex Luthor is so great and why it'll be such a shame to see him less often once Supergirl is gone. Everything from the snark and sarcasm when Melissa Benoist's Girl of Steel discovered his ploy to the classic hubris in assuming he'd truly succeeded just before it all fell apart worked wonderfully, insofar as a bad guy can be wonderful. Of course, he did kind of win in the premiere, though it came at a great cost.
While he was unable to kill a population of the world he hadn't brainwashed, Lex did send Kara to the Phantom Zone using the projector in the Fortress of Solitude. Unfortunately for the villain, he lost his immortality in the process and later had his knowledge of Supergirl's secret identity erased from his memory. A high price to pay, though with no clear way to rescue Kara at the moment, still a win, I'd think.
The real highlight of the episode, though, in my opinion, was Lex blasting Queen's "We Are The Champions" in the Fortress of Solitude after he believed he finally defeated Supergirl. The dancing, the posing with weapons, the randomly tossing grenades for dramatic explosions behind him? They made for legitimately one of the best scenes I've seen in the Arrowverse, and a big reason for that is just how fun Jon Cryer made it.
It was so great it suddenly made me aware of how sad it will be the character has no immediate home in the Arrowverse after Supergirl ends. Sure, the obvious guess is that he could make the jump over to Superman & Lois eventually, but that series hasn't mentioned the greater Arrowverse once and has its own Luthor kicking rocks in Smallville.
I'm sure the greater Arrowverse will find spots for Jon Cryer to portray Lex Luthor in crossovers and such should he be up for it, but can't Supergirl just hang on for another season, so we don't lose a place for consistent appearances? I can always dream! Of course, I love Kara and some of the others who have graced the series much longer, but credit where it's due, Cryer has delivered one of the best versions of Lex Luthor I've ever seen.