Multiverse In Review is the type of treatment that makes reading a bunch of background story for a tabletop game worth it. Source by source, the author is examining every available piece of Fluff in (and out of) the Magic: The Gathering cannon, with (so far) an emphasis on the type of sources that most fans never would have seen, especially in the pre-internet “before time”.
The most fascinating bits are the insights into how the story evolved, and what hidden information those changes reveal. I find these big shared universes very fascinating, and would love to see a similar treatment of, say, the Warhammer 40k setting. A good example, if you want a horizontal slice, would be these three articles on the conception of the Antiquities story the Antiquities comics and the Jeff Grub novel that slots the story into the modern (ish) cannon. Every article is a good read if you’re into that sort of thing.