(I asked members of our discord to vote on what part of the setting to write for in October, and the Eaten Isle won out! So enjoy a bit of history of one of Outer World's spookier locales.)
The Eaten Isle
Adrift in the Shadowed Sea is an accursed place called the Eaten Isle. So known due to its fractured landscape - particularly an inlet sea that formerly hosted a great city and green, fertile lands among other things. It is a dire place, ruined by magic pollution that has stripped away any proper life and leaving only behind bestial husks, twisted flora, and the stubborn dead to wander its many sprawling ruins and bleak landscapes. While certainly not the subject of great ballads and old tales, the Eaten Isle and its history are often on the minds of academics and weavers of magic: it is a shameful, harrowing, and cautionary tale.
So it was
The Eaten Isle was once known as Yeso the Splendid. It was chosen to be the seat of power during the reign of the Divine Rulers in the 2nd Aeon due to its natural beauty, and eventually hosted their holy capital. Great temples and other places of power were erected throughout the island, each intertwined with the forests and lakes around it and connected to the capital via sigil roads. While the Divine Ruler's reign was harsh, Yeso was the Queen of Crystal's favorite part of the realm and thusly spared the most tyrannical aspects of their leadership. Even the Iron King seemed to relax a bit when present on the island - though all living there knew not to cross their monarch, regardless of how his expression might soften.
This peace was disrupted during the 2nd Cataclysm, when rebels from either side of the empire brought the fight to the home of the Divine Rulers themselves. There is no need to go over the various stratagems that brought the insurrection victory, as all are well versed in the stories of how the first mages used the very sigil roads themselves to assault the holy capital, or how Princess Aken lost her duel with the Iron King but finally inspired the people of the island to rise up against him. But needless to say, when this great conflict was ended, Yeso lie in ruins.
Generations passed. From the ashes of the Divine Ruler's empire rose the nations of Akenia and Calian, and those nations grew into fearsome powers themselves. Yeso remained unclaimed by either country, those remaining there happy to rebuild their homes and live quietly among past glories.
Such is the way it went for some time.
During the height of the 3rd Aeon, a conflict erupted between Akenia and Calian. It was one of many small wars the two countries waged, so countless that most of them are forgotten to time. But this one was darker and fiercer than many of the others, as it erupted in the ruins of the holy capital, far away from the soil of either participating nation. Neither the spell-knights or master fleshwarpers there felt a need too hold back so they unleashed the full extent of their power. This drawn out affair ended in a dramatic battle between the Gigaframe Paladinius and a bio-titan called Ragnarok, the two weapons managing to smash each other's spellcore in a final exchange and causing a massive explosion that blasted away all that remained of the holy capital, leaving nothing but a crater behind.
The mana from both machines infused into the very soil and water of Yeso, and even disastrously reactivated the broken sigil roads. The result was a burst of twisted magic that managed to corrupt the entire island and every living thing on it. It's very nature became crumbling and ruined, as if it was slowly being consumed by some unseen force. It was then the Eaten Isle was born.
So it is
After the incident nothing truly lived on the Eaten Isle. Plants grow in spite of being withered and gnarled, the dead walk and even carry on a semblance of their lives before. Insects and other pests have grown to an enormous size after glutting on the poison that infects the land. The crater that once was the holy capital flooded, creating a bay so deadly that even the fiercest of creatures avoid it. The air is thick with a miasma born of arcane pollution so strong that its impossible to safely traverse the surface of the island without a rebreather.
The Eaten Isle is dreadful place, and yet...
If one braves the writhing flora and gnashing creatures of the rotting forests, they may come across the temples of old and learn a great deal about the 2nd Aeon and its glories.
If one is willing to navigate through the mocking and hungry dead, they might be able to purchase some cursed wonder at the necropolis bazaar.
If one finds a way to plunge into the depths of the sea of slime, they may claim whats left of the very weapons that spoiled the splendid isle.
The Eaten Isle is a dreadful place, but it calls to the adventurous and foolhardy.
As long as daring souls think they can discover something in that terrible place, it will never want for new dead to join the ranks of its inhabitants.