The Harrowing is an event and a force of the undead that attacks all across Runeterra, wherever the living might reside. It stared some time after the Ruination had has been a constant threat to the living ever since.
The Shadow Isles were once a beautiful realm, long since shattered by a magical cataclysm. Now, Black Mist permanently shrouds the land, tainting and corrupting with its malevolent sorcery. Those who perish within it are condemned to become part of it for all eternity… and worse still, each year the Mist extends its grasp to reap more souls across Runeterra.
At times, the Black Mist reaches across the seas — and the spirits of the dead go with it. The Harrowing strikes most frequently in Bilgewater. Those slain by the spirits during the Harrowing are damned, their souls dragged back to the Shadow Isles when the Black Mist retreats.
While weaker spirits may only be able to manifest during a Harrowing, more powerful entities can always do so, sometimes even venturing beyond the Shadow Isles.
- Being closest to the Shadow Isles, the island pirate nation of Bilgewater has the most frequent harrowing attacks out of all Runeterran regions and as such their entire culture has been shaped to react to the event. The serpent callers summon beasts to fight the undead. The undertakers chain up dead bodies in floating cemeteries so as to prevent them from joining the undead ranks. The priests of Nagakabourous have also been seen fighting the Black Mist, even proving successful at it.
- Blessed Isles
- Those that survived the ruination have dedicated their entire lives and culture in fighting the undead and the Black Mist. Known as the Sentinels of Light, these warriors are tasked at tracking down the Black Mist in hopes to one day put an end to it. Some treants that survived the Ruination also have a desire to restore the Blessed Isles.
- The Demacian Dauntless Vanguard and the Illuminators have been seen fighting and defending the living from several harrowings. and repelled a harrowing outside of the great city of Demacia caused by Viego.
- The Ionian southern lands has been targeted by several harrowings, especially the island province of Zhyun. repelled a harrowing at the Lasting Altar caused by Viego and an attempt at possession.
- The Trifarian Legion and repelled a harrowing in the middle of the Immortal Bastion caused by Viego, but not before was possessed.