I broadly agree. ExDeath was definitely a tricky smurfer and took me a few goes the first time. I learned of the power of the Samurai $toss that day!

It's difficult to judge difficulty though as it's such a subjective thing - in as much as if you want to grind your characters up to level 99 and master various skills then almost any boss will become a triviality. Likewise, if you don't, it can be a real challenge. When I first fought Sephiroth and Ultimecia (the first two final bosses I ever fought) as a dumb kid they both absolutely stomped me and pushed my trout right back in.