This is quite a good alternative to the usual Inexplicable Maelstrom that seems to crop up from time to time in fantasy worlds. It certainly, in my opinion, beats the 'giant beast in the ocean' origin of such storms.
The only thing that aggravates me is the Ku! thing. I understand why, more or less, but... It annoys me, regardless. A minor gripe on an otherwise quite interesting sub. Go to Comment
I found the historical explanation almost too long and in the end fairly pointless. Sure if gives some back story, but that means you need to incorporate those countries (and there is little to generate the analogs) and sky barges into your world. So what it comes down to: flying warships, evil wizardly country vs others, in a mass battle that ended. A quicker summation might of been more useful.
You can set this farther back in time, so the world has been living with this storm since time remembered. Thus there could be a long standing quest to find the last of the cursed items that caused it. Or the secret to destroying the thing could be "lost to time".
Of course all of this requires sky ships to be in your campaign. And that can make life difficult and change the entire complexion of the world. Well you can get around the Sky Barges:
The storms probably hunts them down. No more great ariel battles. Where once the world thrived via flying trade, all the air ships are now grounded. Thus the world begins to fall apart as cities that depended on trade (and were easily accessible by airship, but not so by the ground) are begining to falter and die off. Go to Comment
I don't read any mention of these being flying ships of any sort. The line open-air gallies seems to indicate an open top ship rather akin to the Viking longship, as opposed to a closed in ship with a deck...rather than an actualy flying ship. Go to Comment
Good luck getting close enough to do so :). The winds are hurricane force and debris could smack you necromancer before getting close enough. The souls are also damaged and individually incoherent, the effects of the Soul Rending wands used against them. Go to Comment
It could be limited by powerful, probably artifical, weather conditions. The strength of this composite being is such that conditions which normally control hurricane movement (water temprature for one) do not have a great effect. It will not stray too far inland, but since so much of humanity generally lives on the sea, this still provides ample opportunity for destruction. Go to Comment
I did not mention sky ships - it was a pure blue-water battle.
and yes, the Aldruku ships are a minor variant on a longboat. They were a lower tech level then the Nyoran fleet - more tribal vs the greek/romanesque.
And to be honest, I had more fun writing the naval battle over the storm. Think I'll need to add toit sometime. Sigh. I keep saying that :)
Even so, they might be chained to the cycles of the weather, able only to manifest when the conditions are right: Dissipating when the storm's energy is spent, then reforming to again ravage the land in search of their ancient enemies, accursed and unable to rest until they have taken the soul from the last of their people's foes.