In my opinion, demons are the weakest. But only until they level up and get their super ability. However, they have Daleb with a terrifying ballista for rapid development. Yesterday, I played with a friend as demons. He got a ballista on the first level. With a double shot, it instantly destroys neutral creatures. And the enemy hero also got a good beating from it (he showed up in the second or third week) - with its help, he quickly destroyed 200 gremlins and their cover. If he had come to me instead of my friend, the Warlock, we would have had to start a new game.