Fortunately, not all of the comics that would make perfect MCU horror films are decades old. For example, the 2018 Donny Cate and Nick Spencer’s Damnation comic would make for an excellent movie because of its high-stakes premise: namely, that Mephisto, the Marvel equivalent of the Devil, has plunged Las Vegas into Hell (and you thought the temperatures were bad before!). This forces Doctor Strange to assemble a very eclectic group of heroes in order to fight for the very soul of Sin City.
If the MCU powers that be are willing to fully embrace horror, Damnation has a bit of everything, including a Big Bad villain arguably scarier than we have ever seen before. Plus, the original comic had cameos galore, including Blade and Elsa Moonstone (the latter appeared in Werewolf By Night). Plus, several Avengers are turned into Ghost Rider-like characters, which could be a budget-friendly way for Marvel to include characters like Hawkeye and Captain Marvel whose actors would potentially only have to provide voices for transformed characters brought to life chiefly through CGI animation.