I used to be the same as others, crawling like insects on the ground, a beast with no thoughts and only knowing how to hunt for food and mate during seasons. Like any other, I was a fool but then it happened, I gained a mind to think. For mere Sapphire Bullet Ant, it was a big deal. Because at that time I can now leave my own colony and start my own.
Magical beasts gain intelligence as they grow stronger however it isn't the same when they turn into demon beasts. The corruption caused by mana would morph their brain in a way that they can no longer think properly. Demons have only an endless desire to devour, to destroy and to kill. They don't have any thoughts about life or even pain. They simply don't feel any of it.
When I failed to ascent to rank Archduke my mana fireback at me until it turned me into a demonic beast. So I became the same beast I once feared when I was a magical beast. A monster that only knows how to eat and destroy.