A lot happened in Supergirl's season finale. Like, A LOT. It resolved hanging plot threads, set up two huge questions, and definitely lived up to its title: "Battles Lost and Won."
After Reign kills Alura, Sam and Mon-El in her cauldron death throes, Kara uses Mon's Legion ring to go back in time for a do-over. While I deeply appreciate the Superman reference, what I love most about it was the epiphany that came before.