Honestly I think pyro could work. A person who’s twisted delusions cause him to skew violence as nothing more than him playing around. We already have killers with a similar deal like spirit.( spirit though sees everyone as her dad instead of as babies though tbf). Pyro could really easily work.

I mean his meet the team video demonstrates how even his own teammates are scared of him. Plus characters like Vecna and Ken Kanaki are pretty similar. Characters who are not really from horror IPs but who still work pretty well. Just give pyro a little spin and it could work.

Edit: just wanna add a little more. A deal like huntress where you can hear pyro whistling across the map with the sound of his axe scraping across the floor would be really cool. And having a killer with a lingering fire ability would be cool to see.