A mir (half-elf) being the only requirement to access an old elven tower seems to be Fridge Logic after a while. The Nyphron Church existed for a millennium and they couldn't figure that one out? This is one of the first hints that Royce is more than what he seems.
This is repeated at the entrance to the Vault of Days. An enormous dragon-like creature's blocking a path they must take, killing anyone who enters... except Royce. This is made even more obvious: Thranic is himself a mir yet he couldn't go onward, and even the earlier incident at Avempartha is briefly referenced as if to remind the readers.
Initially it seems very unlikely how the bloodline of the emperor Novron could've survived for centuries without unfortunate incidents happening to them. The heir and the guardian each held their own amulets that blessed them with unusually good luck and passed them onto their descendants. Not only that, Kile/Erebus is heavily implied to exist and probably had a hand in keeping them alive, especially since one of them lost their amulets.
The tired and weary trio of Royce, Hadrian, and their "prisoner" journey around Windermere Lake towards the Wind's Abby, with the help of a gleaming light to shine their way through. This light was actually the Abby burning down with most of their inhabitants killed.
