I was just thinking about Rogue Legacy, and I realized a lot of the names seem kind of random,so I did some digging. So it turns out that in Muslim Mythology, Al-Khidr or just Khidr is a holy man who seemed to remain young of body, but with a long grey beard. He was said to have found a fountain of life which restored his young age, allowing him to serve god for as long as possible. Alexander the great is said to have crossed a land of darkness for the water of youth. Ponce De Leon lead an expedition many (falsely) believe was to find the Fountain of Youth in Central America (pretty much everyone picked up on this). Finally Herodotus wrote in the histories about a fountain containing magic water that extended the lives of those who drank it. BUT WAIT, THERE'S MORE. Alexander had to cross a Land Of Darkness (name of the dungeon) which was believed to be located in Abkhazia which is located in Georgia (in Asia, not North America). This land is also referred to as Hamson (name of the castle) or simply the Forest of Abkhazia (name of the Forest). But what about The Maya? Well, what do you call the kingdom the Mayans lived in? The Maya (the name of the tower). And of course, what do we find deep within the Castle? The Fountain of Youth.
I think this has some horrifying implications. What if Herodotus, Khidir, Ponce De Leon, and Alexander all went mad trying to find the Fountain and the way they all truly died was at the hands of Castle Hamson? What if all the monsters we find are warriors who went mad after becoming lost within the changing castle walls, transmuted by the power of the fountain just has Johannes is at the end of the game?
I think there might be some evidence to support this in the game considering what Johannes says about how he "wasn't the first one to find the fountain but he will be the last" so it is very possible that this is indeed the case.