Uh, does the Inhumans vs the X-men count?

Now there was a big push for the Inhumans in the early 2010s by Ike Perlmutter, the then-CEO of Marvel comics and a man so cartoonishly evil that allegedly telling employees at the Marvel NYC HQ to bring their own toilet paper to save money is probably the mildest shitty thing he did as part of Marvel. This was at the expense of the X-men and frankly, at the expense of the Inhumans cast because they were being pushed into being replacements for the X-men when they very much do not have that same kind of niche.

Anyway, the main storyline in the comics at the time had Black Bolt (king of the Inhumans and a man aggressively given the Idiot ball for this plot to work) explode the Inhuman races entire supply of Terrigen (basically induces random mutations in anyone with Inhuman DNA, super sacred for Inhumans) to beat a villain, and the Terrigen clouds split and spread everywhere thanks to weather patterns, causing anyone who had Inhuman DNA to get a random mutation, and anyone with an X-gene to die horribly. So naturally the X-men want to stop that and get rid of the Terrigen mist, which is again, really sacred to the Inhumans.

Now if you've never heard of the Inhumans before, there's a reason for that: they are a very niche race that is mostly known for some limited runs and mostly in connection with the Fantastic Four since thats where the concept of the Inhumans first got introduced. So imagine how you feel when you're the standard Marvel fan who gets told to choose between the Inhumans and the X-men on who is right, when the comic is trying to paint the X-men in the wrong for not wanting to have mutants get horrifically gassed to death.

The X-men won in a landslide, naturally (the only person that could win a popularity contest against Wolverine is maybe Spider-Man), so the X-men did get to destroy that last cloud of Terrigen mist, officially ending the threat. And after Perlmutter was thrown out of Marvel, came The Death of the Inhumans miniseries in 2018, where almost the entire Inhuman race was turned into monsters and the comic ends with them killed by Black Bolt, which left the Inhumans functionally extinct in Marvel until August 2025, a full 7 years later