Just from the scrying chamber stories, I don't think all if any of the order of the ninth circle mercenaries will be mage spawn. One was a drawf, his name started with a T, who was hired muscle for the BPR.

Terk, yes, but that doesnt mean he isnt a Mage Spawn. Just look at the Dark Dwarves and Dark Archers from Dragonsgate.

As a fan of the EF I like the Nature's Fury subfaction. Of course I hate that is comes too late to help so many of our underserved/underused pieces from MK and DarkRiders (see trolls, 3 armed bird thingys, tree huggin' elves, etc.)

I'd hoped to see a anti-DC subfaction ability somewhere in the Sorcery set to combat revenent and necromancy (bonestaff), i.e. "Exorcism: Give this unit a special action. Remove any one eliminated unit from the game. Whether it be with the paladin-priests of the EL, druids of the EF, mages of the AE, or even most helpful, with the Galeshi sorcerers.

They will be Mage Spawn, but not neccessarily Mage Spawn in the sense of monsters. They have done ths before with figures like Dragonslayer (who's a Troll but not part of the Elemental League) or Minotrorc ("an Orc who has trained a hideous Mage Spawn to act as his mount and his bodyguard" -- he's a Mage Spawn not part of the Orc Raiders) from Mage Knight Dungeons Dragons' Gate set or the Revenant Draconum (he's part of the Draconium race, but he's not member of the faction itself) from Mage Knight Dungeons Pyramid set.