The Clawed Emperor

The legend goes that long before the Ancient Empire and the Empire of Dercia there was a small kingdom in the Dercian region near where Arborses is located today. The leader of this small kingdom had ambitions of uniting the entire region under his banner. To help in this task, the leader made a pact with some sinister being, gaining a clawed hand that he would use to defeat his enemies in the countless campaigns that followed. 
Several years into his campaign, he had taken the title of emperor, but at this point, he was almost driven to madness with power and was under the influence of the sinister being. His empire was also tired of constant conflict and was stretched thin regarding manpower.
The reign of the Clawed Emperor was marked by cruelty and tyranny. In a desperate attempt to defeat the emperor, rebels and nations that had yet to submit bonded together and raised the largest army the region had seen to that date. The emperors' army were smaller but consisted almost entirely of battle-hardened veterans. The battle that followed was long, hard and bloody, countless people vanished in fire magic or were frozen with ice. The Clawed emperor was defeated, and it said that the emperor's ghost still haunts those who seek power, trying to ensnare them to bring him back to life.
To this date, no one knows what entity the emperor made his pact with. Still, some think it might have been one of the dark gods trying to gain influence in the world. They base that on that since then, other people have gained powers of similar nature to that of the Clawed emperor but still scholars find it hard to gather concrete evidence as the emperor lived several thousand years before the current time but also due to the almost constant warfare in the Dercian region that has resulted in countless destruction of valuable documents and scrolls.