As if American Idol’s grande finale couldn’t get more epic, Katy Perry took to the stage in a head-turner of a dress to perform. The long-standing judge announced earlier this year that this is her final season on the ABC show. Emotions were running high not only ahead of the winner’s announcement, but for Katy’s exit, too. The Teenage Dream singer has starred alongside Luke Bryan and Lionel Richie since 2018. In that time, Katy has handed out critiques to shape the journies of American Idol favorites including Just Sam and Noah Thompson. Now, her career is moving in a different direction. Kat…