The parasiteverse is a hypothetical type of verse where parasites are in every living organism. However the verse itself with be attracted towards other universes. When a parasiteverse is near its heat death, it will bump into a nearby fresh universe and infect it with its parasite properties. The inhabitants living within the infected verse will then have anomalous parasites appear within their bodies. The infected hosts will then become parasites themselves and try and enter any non infected host they come across that is larger than them.
The newly spawned parasites are non-sentient and only have the goal of just being a parasite. Smaller parasites also exist within these parasites and so on and so on. This chain will continue until it reaches the point of the smallest known virus on Earth. At that point their will be no more parasites.