I don't really mind because the boss was challenging enough to me when I played it initially. Of course, if I come along in the future with better knowledge of the system and the attacks to expect, he's going to be much easier, but on the flipside I would have been annoyed if that kind of optimization was necessary playing the first time. On my first time through I didn't really find Sephiroth any easier than Zeromus on SNES. If I compared him to someone like Ultimecia who I completely demolished even on the first time there's no conparison. I would also say Exdeath is especially tough because he does some kindnof crazy petrify attack that I'm not even sure how to heal. It seems like you at least need to both heal the status and then resurrect requiting two actions to undo.