It would appear the royal family also appears to have their heads up their asses.
If a guy as unhinged as Rykell really wants, there's nothing that can stop him. All this talk about "contracts" and "agreements" means nothing to someone who wields as much power as him.
EDIT: Not to mention, the wards around the estate only slowly deteriorate his body, and does absolutely nothing to stop him from using his abilities apparently. What's stopping him from blasting everything to bits in a few seconds and leaving? The wards are useless.