“Ohh the king is dead. This is my chance”-The Usurper
Once a highly respected Noble, the Usurper had an affair with the King’s princesses,(What a playa) Causing the king to exile him after it was discovered. After being exiled he plotted to get back at the king, but his age killed him before he did. Now in disguise he has returned the castle as mourner. He is going to kill for his throne that was taken away from him. After all the throne sits on a stack of cards, and can be easily blown over.
My thinking behind it
He could have been the kings brother. Since the King was wary of his kids he made him next in line.
I honestly came up with this in this is like 30 mins.
Hope you all like 
-NozBugz