The two Bog Witches make their excuses and head out as soon as they believe is polite, returning to give the good news to the boss that she won't be on the hook for a fourth advancement class.
That gives Cain to really think about his new class and how he's going to use it. If he can upgrade one skill for now with another coming to him every twenty levels, he can slowly make his way through all of his summoning skills until he has his full army again. Doing things that way, he can use his Spell Crafting to create the buffs and attack spells to complement them, bringing his combat potential back up to the level that it was before awakening.
The only real difference would be that Awakened attack spells grant much more damage increase than Awakened defensive spells do armor. It's very uncommon to be able to tank more than a few direct hits as a Mythic Awakened. This makes both the weight of numbers and healing ability much more important in the grand scheme of things.
