Monitor and Anti-monitor

Sorry if this is the wrong forum, but can anyone tell me exactly HOW they were created? I read Superman Beyond and the Multiversity Guide and their creation is still unclear to me.

At first I thought (Over)Monitor was the Probe that the Primal Monitor first created to evaluate the Multiverse, but from what I can tell (Over)Monitor and Anti-Monitor already existed when the Probe first went into the Multiverse.

So when and how did they come to be? 😕

Monitor and Anti-Monitor were created after Krona traveled back to the dawn of time to witness the origin of the universe, and inadvertently triggered the creation of the pre-crisis multiverse. That's when the positive matter multiverse sprang into existence, along with the anti-matter universe to balance it.

The 'Probe' that Primal Monitor created to enter/study the multiverse was Dax Novu. He was swiftly corrupted by the stories/narratives he found within the multiverse, and split in two(with his other half being Mandrakk.)