The Unburnt Legacy (en Inglés) - Gregory Parrott

The heirs are reunited, but their bond is a frayed rope held together by shared trauma. Having survived the cold of the Bastion, they now face the Ashlands, a scorched wasteland where the fourth relic-the Eternal Flame-is hidden.

This relic is unlike the others; it does not just show a memory, it forces the heirs to relive the origin of the curse that is consuming Eldoria. As the Warden unleashes a monstrous, flame-wreathed sentinel to stop them, the siblings must navigate a landscape of shifting fire and moral ambiguity. In the heat of the Ashlands, they discover that the King's "sacrifice" was actually a bargain with a darkness they are now forced to pay for. To claim the Flame, one of them must be willing to let go of their claim to the throne forever.