Hold on a second, I couldn't remember/fully interpret what happened at the end of the game. Unicorn, I agree, he did die.
I finally remember now! The explosion of the ultimate machine took the secret base with it, so Shauna, Calem/Serena and the player have to run out just in time before it collapses. Everyone else inside dies.
But anyways, the worst thing about the death of Team Flare is that nobody gives a crap. Sycamore is just like "so sorry about Lysandre's behavior" like he's his babysitter or something. Everyone else is just happy they're gone. I don't care if they were trying to destroy the world! A lot of people knew that their goal wasn't all bad, it's just what they were doing wasn't right! And Lysandre even learned his lesson at the end!
THE ENTIRE KALOS POPULATION IS MADE UP OF COLDHEARTED FREAKS!