6 decades books

When dozens of territory "bubbles" swap between two parallel Earths without warning, a Chicago vlogger and a displaced wizard find themselves stranded on opposite sides of reality — each holding half the key to a catastrophe neither can see coming. Kaelen, an engineer with a camera and zero combat training, wakes to silence in a world of feudal warlords and untamed magic, where he discovers he can reduce spellcraft to mathematics — and accidentally invents the weapon that could shatter both worlds. Isadora, a scholarly mage of terrifying composure, materializes in modern Chicago with three mana nodes, no English, and a crime boss for an ally, only to realize the city''''s electrical grid is a ley line network no one knew existed.