What was the scariest scene that you have read in any X-Men comic? This includes X-Men comics from Uncanny X-Men, Astonishing X-Men, X-Men and many more. Here are two scenes that stood out the most to me:
1) Jean Grey destroying the planets in the "Dark Phoenix Saga."
This was technically not a scary scene, but it was a scene that stood out to me for a long time as we see Jean Grey destroying planets when she becomes the Dark Phoenix in the "Dark Phoenix Saga." This was a pretty intense scene since the idea about destroying other planets is a frightening thought and having a super mutant destroying planets out of nowhere can be really intense to look at.
2) Kitty threatening to phase an axe through Colossus's head in "Astonishing X-Men"
If you had read Joss Whedon's run on "Astonishing X-Men" the "Torn" arc, then you'll definitely remember the scene where Kitty is affected by Emma Frost's hallucinations and there is this one nightmare sequence that Kitty has where she threatens to phase an axe through her lover, Colossus' head after Colossus let the X-Men take her baby son away from her. This scene was truly creepy and dark as you're wondering to yourself about what Kitty is capable of doing. Not to mention, she is threatening to phase an axe through her boyfriend's head! Now, that's dark! This scene is probably the scariest scene I have seen in Joss Whedon's run of "Astonishing X-Men" since everything felt so real and Kitty can be really scary when she's mad (at least in this dream sequence).
Those are my two scenes so far, but you can name a scene that was shocking, scary, disturbing and creepy to you.