Dread Seven

Dread Seven is a super virus that exists in a dimension parallel to our own. It is due to an "interdimensional overlap", where the furthest reaches of two negative-energy dimensions touch. It is an extraordinarily rare event called a Cross-Over Vacillating Imponderable Denomination(COVID).

Dr. Cerko Kwa-Dratika, the foremost expert on "interdimensional interrelations", spent many years researching this.