Is it even possible to make an even harder raid?

[Firepower]

I remember difficulty, where even though it drops the best items in the game it is completely ignored because nobody can kill it. When Absolute Virtue was first introduced it went years and years undefeated by conventional means (people glitched it and pulled it to tether lines where it stopped attacking which was fixed pretty quickly) Even so long that the playerbase was crying out to square enix to release some sort of information on how the heck to beat it, in which square then released a video of the dev team beating it, which still offered little to no information.

When a boss has insane regen, can instacast a bunch of teir 5 spells or cast meteor uninterrupted or even worse when almost dead just benediction himself, that was the point of stupid difficulty. Nobody enjoyed that.

[Garlyle]

Absolute Virtue

Absolute Virtue fascinates me because I don't believe his 'solution' ever changed throughout the entire time he existed, but it still took people years to realise that a boss actually reacted to their actions and had what were basically unique mechanics (For the unfamiliar: Absolute Virtue had access to every "Two hour ability" in the game, to use at will - these being player character super abilities. However, if you used a matching 2HA right after he did, he lost the ability to do it again). It seems, in retrospect, so astoundingly obvious - especially in the modern era of MMORPGs. Of course, even knowing that back then, he would have remained hell for the other nonsense like instacast top tier magic.

But yes. XI's had a few bosses over the course of its life that were examples of difficulty that didn't make for a good player experience, usually through obscene stat allocations.