Comics without plot twists would make for a totally different - and much worse - medium.
With many series falling into the trap of rehashing the same basic hero-fights-villain-and-wins narrative, anything that changes this formula serves to create the kind of story that keeps people coming back for more, as finding out your favourite character isn't dead - or that your favourite hero is no longer a hero - makes for the kind of exciting developments that you simply cannot ignore.
This is arguably why many of the most revered comic writers are those who are responsible for the industry's most insane curveballs - such as Hickman's runs with the Avengers and X-Men, or literally any series touched by the gentle madness of Alan Moore.
That said, the best plot twists are also some of the most simple, as they're things we totally could have predicted, had we been lucky enough to pay attention to all the sneaky clues artists and authors dropped in for us. Reading back through a comic and seeing all these tasty little hints - or even being savvy enough to spot them the first time around - really enhances the sense of mystery you experienced, as it adds an extra way for you to become immersed in the universe and the medium.
10. Scott Summer's 'Secret' Brother
Vulcan - known also as Gabriel Summers - came as a huge surprise to countless Marvel fans upon his first appearance in X-Men: Deadly Genesis. Only, it really shouldn't have been, as we actually already had been told about his existence a whole twelve years before the comic.
In X-Men #23, the practically omnipotent Mister Sinister asks Scott about his 'brothers', which Cyclops is naturally incredibly curious about, given that at this point in time he was only aware of Havok being his brother.
While Sinister tries to play it off as 'having forgotten' how many brothers Scott had, this is clearly a lie, as Sinister is repeatedly shown as a supercomputer-level genius, meaning there is minimal chance he 'just forgot' the leader of the X-Men didn't have an extra sibling.
Although you wouldn't expect this reveal to have happened over a century before it was relevant, there's something incredibly cool about the fact that Gabriel's character was mentioned to us long before he ever appeared in the actual comics.