The Ur

Description
The Ur can not be seen or comprehended by mortals, but are insectoid creatures from a higher plane of existence that leave spherical holes in reality that hover and grow slowly as they chew holes in our reality. Staring at an Ur Sphere, one of the holes, causes serious constitution and wisdom damage, as such things should not exist. They occasionally convert beings within the reality they are consuming to serve their ends, and the result in Ur Cultists, faceless wraiths with strange mechanical devices on their hands that can trigger an Ur sphere.

Killing the Ur
The only human who has successfully killed an Ur cultist and dispelled an Ur Sphere was Geiger, who died in the process. He got better. Said encounter resulted in massive casualties, dozens dead, and the entire party of strong mages, warriors, and paladins all dead.

The Ur Echo
The Ur has invaded the world of Allhailkingbob once before, which resolved in the current hero's summoning a race of Ur-eating Ladybugs. Currently, the world is being attacked by echoes of the Ur, shaking the world to the brim, summoning variants of the Ur Cultists, and even Ur themselves. A small group of heroes are trying their best to stop the echoes, and are working with Geiger to cease it. Izzander, a mysterious man, might be the only one who can stop it, forcefully, though Kalvin, the god of Black Holes is offering to eat them in an "all-you-can-eat Ur buffet," though he is of dubious morality.

Plot
Many books have been made about the Ur, and their effects on the space-time continuum, however many of those books have been lost. Some of those books are in the Library of Olivia, which was burnt, the Night Elves, who are unwilling to share, and unknowing of their priceless knowledge. Most of those books are likely in the hands of the mysterious Izzander, the top scientist on the topic of the Ur, and the one key to stoping the Ur Echo.