Freya once thought the Tundra was the worst thing that could happen to the world. The Blood Moon Plague proved her wrong.
The name of Freya's hometown has been lost to the history books. It is now known as Hell, the Land of No Return, or the Abandoned City. Its once vibrant streets are covered in fog. None approach. But if a lost traveler were to venture near, they might still hear something: screams and shouts to chill them to their bones.
As a Nightguard, Freya and her fellow sentries were well-protected at the city outskirts inside a tower with plenty of food when the Blood Moon came. Never would they have guessed that one day they would not be defending against invaders, but preventing former family and friends from ever getting out.

But someone always slips through.
Words cannot describe the terror on a traveling merchant who, after wandering off a mountain path, came face to face with the monsters of Hell. Crooked, misshapen human things covered in grotesque scarlet crystal flower petals, their jet black eyes full of darkness and suffering.
The next thing the merchant knew, the monsters had fallen to the ground with a glint of cold steel and he was being dragged back to a sentry tower by a shadowy figure. This lady—his unfriendly savior—said nothing as she called for a doctor to give a full examination.
A strange figure in a bird mask examined the merchant carefully for a disease referred in hushed tones as the "Blood Moon Plague". Fortunately, he was allowed to go free with a strict warning and ominous feeling that if he had shown any signs whatsoever of the plague—whatever that was—he would have been treated very differently.

Philly, investigator of all strange diseases, originally named it the Blood Moon Plague upon hearing Freya's harrowing account.
The first rule of plague is to prevent its spread, which Philly urged the sentries to do. He struggled to come to terms with the mysterious illness that seemed to spread via crystals and fog, turning men into beasts with great speed.
Freya was the exception who, once she recognized in her body the signs of infection, merely collapsed. So she was kept under observation. Eventually, as if by some miracle, she began to observe her own recovery. Her body's natural defenses began to survive, even thrive. Now she is the only one who can walk through Hell with impunity. Great strength has also come through the inactivated remnants of the disease in her body.
Freya has since become a key member of her fellow Night's Guard survivors: a lady immune, with super strength, tasked with keeping the gates of Hell firmly closed.

Hades was once called Metiya, a tiny city on the edge of the wilderness.
Life in the age of ice and cold was a tough adjustment. The City's Furnace was often short of materials. It was in these desperate times a strange visitor arrived with a promise of abundance if he could run a little "experiment". It was a success at first. People gained great strength and energy even without food. They could walk outside without feeling the cold. But grotesque deformities soon followed, rage, and a terrible madness.
In the end, the vast majority of "subjects" lost all reason and began attacking their neighbors. A fog descended at roughly the same time over the whole town, either a cause or consequence of the plague—Freya cannot say. She was then infected. As her eyes turned cold and red and dim she looked upward. The full moon should have been silver-gray. It was completely covered in blood.
That is all Freya remembers of her long recovery. Now there is only the hope that just as she has healed, Hell's residents can do some too.

• Hall of Heroes