What about something Bigger?

In this scenario this particular package rather then only affecting a couple of people or a individual whether to spread something or change even more people or just specifically for their specific alteration. This however, proposes the concept of a purposeful group altering device, a mass changing item, a shifting creation, etc. A massive bomb, a impossibly infective virus, something that aims to change people through their surroundings, mass reality altering, however it might go about its methods; magic, science, modern, ancient, whatever the case it is a significantly more powerful or perhaps less subtle item then the ones found on the normal branches. So do tell, what Item of Mass Change is at the door? Or is it not at a door? And how will it truly shake things up?