I played through all the campaigns in The Restoration of Erathia, The Shadow of Death...
but I can't complete the second mission in Armageddon's Blade (I only played it once, but it was quite difficult to fight against other mages) maybe I'll manage it now =) :)
and I can't complete the Witch campaign (turn 2 or 3) there are hordes of undead, especially skeletons... I don't know how to pass it...:(

because of these two campaigns, the last one doesn't unlock...