The DC Multiverse is essentially a storytelling device that ties together numerous materials published over the past 80+ years. Throughout the years of publications that made up the DC Multiverse, the consistency of the verse has sparked much controversy. This is due to various changes, continuity errors, and different interpretations of them that have been written by various authors over the years.
Despite this, many efforts have been made to reconcile these various inconsistencies. In the '90s, Grant Morrison and Mark Waid created Hypertime to explain continuity errors, but it's sort of become a buzzword that writers haven't used consistently over the years, with no "official" in-universe definition. Following declining sales of the New 52, DC co-publishers Jim Lee and Dan Didio decided to vote against restricting writers to strict continuity (i.e. New 52 continuity, Post-Crisis continuity, etc.) and wanted to open up a wider playing field for potential stories by making everything canon. The problem we have been running into is that different writers often write independently of each other, adding new concepts to the older ones while ignoring or only somewhat acknowledging the works of the other writers. This is not always the case, as some writers pay considerable attention to the works of certain other authors, but even then there are some degrees of independence.
There have been other attempts to explain the changes, notably with the Metaverse with which Geoff Johns came to shed light on the various changes taking place in the DC Multiverse or Scott Snyder's attempt to undo the contradictions of the DCU with the end of Death Metal, which not only gave importance to every DC story, but the multiverse also became its own sort of Omniverse, but that was changed literally a year later with Dark Crisis which tampered with all of that.
Regardless, the above circumstances cause the following problems:
- Chain-scaling issues: Several characters have derived their statistics from complicated chains of power scaling based on various distinct iterations of the cosmology that do not fit with each other, leading to ratings that do not fit with many of their storylines. For example, Perpetua of the Rebirth continuity does not fit DeMatteis' interpretation of the DCU as his vision is a different from Scott Snyder and Grant Morrison's throughout 21 despite some similarities.
- Incongruent Ratings: For example, many of DC's cosmic entities are rated tier 1, even 1-A, even though these characters have never demonstrated a power level that high in any of their stories. Through scaling across different versions of the cosmology, they end up with a rating that is incongruent with their true power level as written.
- Incompatibilities: Different authors have written incompatible versions of the cosmology regarding different dimensions and higher realms, in terms of how they are defined and fundamentally function. Sometimes, although this is not always the case, certain authors tend to contradict themselves. For example, Grant Morrison's previous stories described the Fifth Dimension as a higher mathematical dimension while in other stories he described it as an imagination. In James Tynion's stories the Great Darkness is the Dark Sphere of the Gods around the Dark Multiverse while in more recent stories by Joshua Williamson, the Great Darkness is a Primordial Darkness that predates even the Overvoid.
