Reality warping mutants.

[Traab]

What happens when they collide? I know about M-Day when the scarlet witch really screwed up, but how does that effect fellow reality warping mutants? Are they caught off guard and lose their powers? Can they hold onto them because they can keep reality shaped as they see fit? Is it a matter of scale? Meaning some are just so much more powerful that it doesnt matter they can shape reality on a whim, this one is much stronger at doing it so he/she wins?

[NerfTW]

Well, in Scarlet Witch's case, she's not omnipotent. At least one mutant, and probably others, was able to see through the new reality. And when she mind wiped Wolverine, she only wiped his planted memories, resulting in all of his real ones coming back.

Proteus has a weakness to steel, since he can't directly affect Colossus. So he's not all powerful.

Legion only warped reality in a limited area surrounding Utopia. More powerful beings like the Phoenix force had limited awareness of the altered state of reality. All telepaths were capable of seeing through it and had to be imprisoned.

Even Morganna's spell to remake the world into Camelot right after Heroe's Reborn failed simply due to willpower and familiarity. Thor broke free when he realized the Rainbow Bridge was missing and he couldn't hear his father. Cap broke free almost instantly by being in a familiar position of leadership of the Avengers. More Avengers followed suit when faced with the statement that reality had changed.

I'd say it has to do with who's power is greater. I doubt her alteration of earth affected beings like Galactus, the Tribunal, or Eternity.

[thubby]

I'd say its on an entirely case-by-case basis.

the various eldritch horrors that bend reality just by existing probably don't care much about the likes of Q or a trickster. but chtuhlu is unlikely to deliberately send you into the sun.

similarly, entities that use effort and will to shape reality usually do more impressive things, but are subject to even mundane forces if caught unawares.

[Traab]

Yeah I didnt think it would have effected the multidimensional beings, or the intergalactic ones, I was more thinking of the sizeable number on earth at the time. Franklin Richards for example. Was he hit by M day? This is someone who can shape reality on a galactic level.

[Bitter]

I think Franklin was depowered at the time.