Monitor-Mind the Overvoid was the void outside of every creation, blank and white. To the Monitor-Mind, creation, logic and reality is nothing and all falls short.
Within itself, though, the Monitor found the flaw and acted to contain and bottle it. Sending a probe to study the flaw, the Monitor-Mind created the Science Monitor Dax Novu. Upon entering, though, Novu was affected by the cosmic bolt created by the mad experiment of Krona and was forced to split into the Monitor and the Anti-Monitor.