'Multiverse of Madness' – thanks to Sam Raimi in particular – is not your average Marvel movie.
Yes, there are some pretty gruesome and brutal scenes and yes, someone dies. The number of on-screen deaths is surprisingly high, actually, considering that 'Multiverse of Madness' is still a Marvel movie after all.
If you have yet to see 'Multiverse of Madness',
MAJOR SPOILERS AHEAD!
With Wanda basically turning into a supervillain here, it comes as no surprise that she's responsible for almost every important death that happens in the movie. Wanda's goal is to steal America Chavez powers so she could get to her kids in alternate universe, and she won't let anything – or, as it happens, anyone – stand in her way.
First one to die is Defender Strange, a variant from one of the alternate universes, who fights a powers-stealing demon alongside America Chavez, trying to protect her and seemingly failing. The demon stabs Defender Strange fatally, but before dying he opens a portal, sending America to the MCU reality.
Most casualties happen during a battle in the Illuminati universe, with Wanda fighting – and eventually killing – the Illuminati in different ways.
Black Bolt is killed first, and then Lashana Lynch's Captain Marvel is crushed under fallen debris; Wanda brutally kills Captain Carter with her own shield and then, finally, Professor X, who tried but failed to save the alternate universe's Wanda (a "good" one), – snapping his neck.
But that's not even the end of it. Back in the MCU reality Wanda is holding every sorcerer in Kamar-Taj hostage, and after one of the sorcerers managed to free herself and destroy the Darkhold, Wanda loses it completely and burns the sorcerer alive with America Chavez and Wong witnessing it.
Yet another version of Doctor Strange – Strange Supreme, villainous Strange's variant – is killed in 'Multiverse of Madness' too; this time it's MCU's Steven who kills him(self?) after finding out that this variant, trying to defeat Thanos, was corrupted by dark magic leading to the whole universe being destroyed.
By the end of the movie MCU's Wanda almost kills alternate universe's Wanda, and then, back in MCU, upon realizing everything she's done, tries to kill herself, destroying the castle with herself inside.
Having witnessed the list of victims this long, fans are now divided over the treatment Wanda got in 'Multiverse of Madness', with some even saying that she was never this evil in the comics. The overall cruelty and lack of basic sympathy to those around her make Wanda in 'Multiverse of Madness' hard to sympathize with. Other fans, though, point out that this is actually a brilliant – and very well thought-out – character development, with Wanda making very questionable choices in 'WandaVision' and then going full-on super evil mode in 'Multiverse of Madness'.