King Of The Fire Dragons

For 1000 years, the war between dragons and humans waged on. One day, a great dragon with unfathomable power appeared and single-handedly ended the war, forcing both sides into peace under his immense strength. Over time, everyone began to learn to coexist with one another. Although some humans and dragons refused to live in peace, they were seared with burns of vengeance and hatred. They were banished from the mainland and found homes within a dark wasteland known as the Void. However, something sinister emerged: a creature that has decimated entire towns and villages, leaving nothing alive and poisoning the land. The creature claimed that it's nothing more than an omen of the tragedy that is to come to usurp the king. What is this creature and what is threatening the Dragon Kings rule?