Who are DC's Time Masters and what is the Divine Continuum?

gamesradar.com:

In the opening pages of Flashpoint Beyond #0, Batman infiltrates a strange hideout containing artifacts from decades of DC stories. He’s seeking a watch that belonged to Janey Slater from the Watchmen universe and has enlisted Doomsday Clock characters Mime and Marionnette to help. 

Though the trio manages to find it, there's one artifact that they all gloss over: a picture of a DC team dating back to the Silver Age. This picture becomes important when one of its subjects enters the story in a big way, and the mysterious hideout and all the artifacts within begin to make a whole lot of sense. 

That team is the Time Masters, and at the end of the issue, their youngest member Corky Baxter shows up in the Batcave. Corky warns Batman that his investigation is going to "open a can of worms" when it comes to the DC timestream, and if Batman continues what he's doing, Corky and the Time Masters are "going to make [him] eat them..."

The worms, that is.

But just who are the Time Masters? Where do they come from, and what does their appearance in Flashpoint Beyond #0 mean for the DCU? Here’s what we know.

If you're a fan of the CW's Arrowverse shows, you may recall the TV version of the Time Masters as a council of authorities in the show DC's Legends of Tomorrow, who govern the laws of time travel and often have dubious reasons for doing so, similar to the TVA in the Loki streaming series. 

And also similar to the TVA's 'Sacred Timeline', Flashpoint Beyond #0 indicates that the returning comic book Time Masters may have their own term for the entirety of all aspects of DC continuity from the Multiverse, to the Metaverse, the Dark Multiverse, the Omniverse and beyond: the Divine Continuum (get it? Divine Continuum = DC).

While the