I didn't like Zenos in Stormblood. Him refusing to kill you cause you bore him, 1st time, then to see if you become stronger, 2nd time, only to have you beat him the 3rd time just felt... bad. However now that we know he has always had dreams of the end of days, and that his resonance wont really let him die, he "might" be more interesting in Endwalker. I do think it's time for a villain that is just evil because they want to be. If every villain was relatable or understandable then the term evil starts to have no meaning.