Prince Ace was not the firstborn prince of the Demon King. He was not the second or third, nor even the fourth. He was the sixtieth son of his father. Yet, despite this, he managed to rise above the others and earned the title of the Ace of the Demon King. Consequently, everyone started referring to him as Demon Prince Ace.
His father always regarded him as a skilled and capable warrior. He dispatched Ace on missions across the Demon Empire and praised his achievements. Or at least, that was what everyone believed.
However, only Ace knew that his father did not truly view him as the heir. Despite giving him an opportunity to gain experience, the Demon King saw him as merely a dependable prince. He was not seen as someone fit to occupy the throne.
This realization irritated and motivated Ace to prove his father wrong. Yet, he had not anticipated the old demon summoning him to his office one day to deliver a piece of rather unpleasant news.