An Alpha's Wrath 1
The curse is a demon sealed in his heart after his father managed to release the curse of loneliness in their family and get his death after 100 years by knowing the devil resides in the heart of his descendants.
Alpha previously knew that the curse was not that easy to escape because of the terrible demon figure in exchange. To be more precise, the father of alpha Draco made a deal with the demon to release the curse in his offspring on the condition of giving the body of one of his children as a host container when resurrected.
It's a terrible family indeed, which is why the territory held by alpha Draco is known as the cursed territory because most of its people know how to curse and other curse spells, as well as the binding oath itself.