Actually, it turns out that the Myrmidons were going to fight with Soulblighter in his attempt to destroy the world, but one time while the legions of the Dark were spending some time in these time-share condos on the beach the Ghols, restless pranksters that they are, locked the Myrmidons in the shower stalls with the hot water running full blast. The resulting damage to the Myrmidons' bandages led them to abandon Soulblighter's army in disgust for the insult that had been dealt them.
My source for this information: Xzzy's tru7h.org (http://www.tru7h.org), especially the Tome, an institution which I'm sure would make all you story-perfectionist Asylumers (meant in the most positive way possible, of course :) collapse spontaneously in apopleptic shock. ;-) Erm... but come to think of it, the new Tome (that contains the above story) isn't up yet... hrm... never mind. :)
-Tsao