Okay, close your mouth and don't be so shocked. I know what you're thinking: "You put Theo on the overrated list, but you put this killer dude on the underrated list, what is wrong with you??"
Well, the difference between Deucalion and Theo is: When he was a young child, Theo killed his sister for no reason and doesn't really have a real drive, but Deucalion on the other hand tried to make peace with the hunters and had his eyes electrified by the biggest a-hole there is. So, can you blame him for wanting a little revenge? And if you think about it, no one really liked Chris Argent in the beginning either, but then became the greatest badass dad there is, even when his daughter was killed, so let's give Deucalion a little slack here. Plus, he did end up helping Scott and his pack in the end, without even killing anyone. You died with honor my friend and ended up on my list, so good for you.