15Impossible: Atomos (Final Fantasy V)
You can explain away Atomos’ difficulty by saying that he's the last line of defense for Castle Exdeath's protective barrier, but that doesn’t make this boss fight any less ridiculous. There are more than a few ways to cheese your way through this fight, including taking advantage of Atomos’ lack
of Sleep immunity. Still, the Barrier Tower guardian’s penchant for Comet attacks that can KO the entire party leaves little room for error, and unprepared players will likely fail a few times before they figure out the AI’s plan. See, you have to fight him with one party member down in order to avoid his Comet attacks. Once again, this mechanic is not intuitive to any player, much less a rookie. Kind of makes you wonder if someone had the right idea they said Final Fantasy V was too hard for North American gamers.