Very. One of the most stubborn dogs I've had to train.

[It had taken him a long time to get through the basic commands, but Cerberus had the right temperament for a service dog, not to mention he was smart. He had to wonder if Cerberus' slowness at being trained was just stubborn obliviousness or if he got bored and kept forgetting commands. Either way.

He paused, not wanting to just make it seem like Cerberus was a handful, since this was the most interested he'd seen Heine with all the dogs so far.]

But once he's trained, he'll be a very loyal and protective dog.