I’ve been writing a series of posts about crossovers, and I’m almost ready to bring it all together, but first, one more point about multiverses.
It makes sense to me that if a franchise has a multiverse, then any crossover with any part of it establishes being able to crossover with any part in a multiverse sense. Here’s a (certainly incomplete) list of franchises whose multiple continuities are established to be a connected multiverse and/or split timeline. (Notably, most “new universe” crossovers actually include at least one of these, making them effectively count the same as multiverse crossovers.)
1. The DC multiverse (a total mess because they tried to get rid of it and then brought it back in an incomplete way, but still, it exists)
2. The Marvel multiverse
3. The Transformers
4. Star Trek
5. The Legend of Zelda
6. Fire Emblem
7. Teenage Mutant Ninja Turtles
8. Super Robot Wars
10. Mazinger Z
11. Devilman/Violence Jack (overlaps with Mazinger Z, possibly to the degree of not being seperate)
12. Getter Robo
So, for example, connecting any version of Transformers effectively connects all of them, or at least that’s the standard I’m going to be using.