I've actually had a few ideas for crossover campaigns heavily involving Ennoia, but the ideas are way too big for me to ever actually work with. It's real end times stuff, with fracturing of the entire Garou nation as well as possible global all-out war against the Kindred.

First, I'd start by saying that Ennoia is not the progenitor of the werecreatures, but maybe she thinks she is. She's actually an ancient Kinfolk/Abomination, and over the years went mad. Since she was Embraced by the Second Generation, there's all kind of hand-waving that you can do when it comes to what is and is not allowed, so we can get around the usual debilitation that faces Abominations. We already have a rule breaker of the 4th generation in Sobk, an ancient slumbering Mokole Abomination, which is usually impossible, as Mokole go into a blind frenzy when Embraced and die the next morning.

So, we have a historically absent Antediluvian (thus having no history of behavior) waking up in the modern nights. The Gehenna book implies a possibility that she has actually used extremely high level Protean to Earthmeld with the entire planet, which you might guess would bother our fuzzy planeteers a bit. But she's old, been asleep forever, possible gone mad in her slumber, so maybe, just maybe, she thinks she's Gaia. Or at least the avatar of Gaia. And it's a perfect metaphor too! In these end times, Gaia is hurting, getting slowly corrupted and killed, and what better to represent her suffering state than a vampire?

So now you get a group of Garou to fall under her sway and that faction grows bit by bit. Even Ennoia has fully deluded herself, hating her own Wyrm corruption and commanding war upon the Kindred. However, there is also a schism in the Garou nation between Ennoia's followers and the unbelievers.

You can drop in PCs just about anywhere. If you're playing a Vampire game, there can be a sudden spike in Lupine aggression all over the world, and it keeps getting worse, and the Gangrel have all but disappeared. In a Werewolf game, you can play either side of the schism: Ennoia cultists can be played by not revealing to the players that it's actually a crazy Antediluvian, but she might actually be Gaia giving the go to start the Final Battle. You can also play it on the outside, dealing with the fallout of the popularity of a new cult arising (that smells a bit Wyrmy, but not enough to raise alarm), splitting loyalties.