He’s also the focus of a nasty fight that’s coming up with Patch 3.2. Sephirot’s boss battle requires no less than a team of eight level 60 players looking to get slapped around by thousands of pounds of sentient metal (rock?) and chains.
According to the a new sneak preview of the fight, “Sephirot, the Fiend, was a deity once worshipped by a tree-like race native to Meracydia. Brought into being for the sole purpose of repelling the Allagan invasion, Sephirot inflicted ruinous losses upon the imperial army before finally being subdued and imprisoned in the central facility of Azys Lla. And now, millennia later, this immensely powerful entity threatens to awaken, his vengeful dreams disturbed by the careless ambitions of Archbishop Thordan VII.”
So really, you’re fighting him because someone else woke him early from his nap. Seems fair.