The Warden's Gambit (en Inglés) - Gregory Parrott

The Ashlands are behind them, and the four heirs have four relics in their possession. But the final piece of King Atheron's soul-the Crystalline Heart-remains out of reach, guarded by the relentless Warden. As the siblings track the Warden to the edge of the world, the hunter finally becomes the host.

In a shocking gambit, the Warden lures the heirs into the Catacombs of the Lost, where their true identity is finally revealed. The Warden is not an ancient monster, but the King's forgotten fifth child-a sibling banished and erased from Eldoria's history to hide a devastating royal secret. Now, the heirs must decide: do they finish their father's ritual to save a corrupt kingdom, or do they side with a sibling who has every right to see that kingdom burn?