The Phantom Castle (The Way of the Shaman: Book #4) LitRPG series

What can a game clan accomplish without a castle? The answer is obvious: nothing. Therefore, the main objective of any leader in a game world is to acquire a base of operations. Finding himself in exactly this position, High Shaman Mahan, leader of the Legends of Barliona, accepts an offer from the Emperor and the Dark Lord to vanquish the army of Phantoms that has inhabited Altameda, the phantom castle.

However, this seemingly ordinary quest sets in motion such a momentous chain of events that the Shaman can do nothing but resort to his intuition and act on instinct. After all, a player who is being hunted by the three top clans of the continent at once, can do little else...