YMMV / Supergirl (2015) S3E23 "Battles Lost and Won"

• Anti-Climax Boss: Selena and her cult are taken down pretty easily.
• Like You Would Really Do It: Come on, does anybody really think that J'onn, Mon-El, and Winn are gone for good? David Harewood had already stated that he was staying for Season 4, and Mon-El is given a Commuting on a Bus setup to be called in if Kara ever needs his help, while Jeremy Jordan is also returning, just in a recurring role, so he'll also be Commuting on a Bus. Similarly, while it was possible that Sam and Alura could have been Killed Off for Real by Reign (especially as the last quarter of the season had been setting up the possibility of Alex adopting Ruby), it was highly doubtful that Mon-El would have died, especially given the spin-off potential for a Legion of Super-Heroes series.
• Take That, Scrappy!: Even with all the development he's undergone, it's hard to not be amused that after all the hand-wringing over whether Mon-El would end up with Kara or Imra, he gets neither. The knife is twisted further when you realize that Imra was fully aware that Mon-El needed to return with her to the future when she broke up with him. Even stranger, as their marriage was specifically of the political kind, implying that the reason for it still exists in the future, and yet they decide to end it because it's "not based on love".
• Unexpected Character: While he hasn't yet appeared in person, there was little indication going into the finale that the original Brainiac would ever play a role on Supergirl.