'I feel like I've been seen through, but that's impossible.'
Damien only believed that he could solve everything in four days because he didn't have to travel the long distances anymore. Now that he'd been to the Eternal Sanctum and the Volcanic Spires, he had enough points across the map to be near any destination he might want to reach.
He was able to cancel distance from his place inside of the Dragon Lord's magma channels and return to the Prison Master's manor without any trouble at all. Unfortunately, he couldn't enter the Eternal Sanctum with the same method, but that was obvious. If people could freely enter and leave by canceling distance, then it wouldn't be much of a prison to begin with.
More than that, what concerned Damien was the strange feeling he got when he first stepped on the property.