Karl was relaxing in his room, pondering the changes of the last few days, and how the progression of the beasts hadn't been quite what he had expected them to be. Somehow, with her love of the dark, he had thought that Rae would naturally pick up another stealth skill, but from experience, it was the most deadly of attacking skills that she was most in tune with, and the stealth aspect of her evolution was only a secondary facet that allowed her to get close enough to her targets to attack.
Thor using his tail to create Earthquakes hadn't been too far out of expectations, as it still activated with lightning energy. But Hawk learning fireballs just so that he could torture the water mages more effectively was completely on-brand, even if Karl had overlooked it until it happened.