Light Returns (en Inglés) - Ivy Water

Ishian leads the army to descend into a cursed realm where reality bends, and death doesn't end. The Necromancer waits in the dark-ancient, patient, and desperate to keep the world enslaved. To stop it, they'll have to destroy the source of its power. To destroy the source, they'll have to survive what should be unsurvivable.

The Boon-an ancient force older than memory-flows through them, burning with alien energy. It keeps them moving. Keeps them fighting. Keeps them alive long enough to reach the end.

But every power has a price.

In Light Returns, the trilogy concludes with the reckoning that was always coming. The world held its breath waiting for salvation. It has no idea what's about to be given.