Celtic Heroes

I have searched for the last 2 days for some specific trainers, Knox the ice mage trainer and spellbook merchant Aspen the Druid. Online it describes them as being at Farcrag Castle. They are for sure not there, any help would be truely appreciated

Knox was an old NPC and can no longer be found in the game, you would most likely be looking for the Mages in the Guild Alley now.
Spell book merchants can be found here:

Thank you so much!