The Shadowlord: First major villain of Final Fantasy XI, owner of a tragic backstory, leader of beastmen, and wielder of an absolutely killer sword. The last one is the big thing you’ll have a chance to loot from fights against the Shadowlord starting on August 30th, so it’s perhaps the most pertinent to mention. Sure, it’d be nice if you could loot yourself a tragic backstory, but the legacy code from PlayStation 2 renders that impossible.
Yes, that’s the whole point of the event. Fighting against the Shadowlord on any difficulty, you’ll have a chance to loot either his one-handed sword or his two-handed sword. The odds of grabbing one increase on the higher difficulties, though, so there’s a reason to get your friends together and really challenge him instead of just spamming the first fight against him at level 60. But you still have a chance even then, at least until September 30th rolls back around and he gets a firmer grip on the weapon, so to speak.