Cassie Nova. I loved her.

Onslaught

@AgeofHurricane said:

Cassie Nova. I loved her.

sometimes I still get worried about where she'll turn up next. like, genuinely scared.

now I won't be able to sleep tonight.

The Human Race. And I mean most of the humans, sentinels, etc.

@Edamame: I think that Mr.Sinister is more powerful, but Bastion is more dangerous.

Meh, Cassandra Nova can be defeated...any enemy that can be defeated isn't that terrifying, I mean yeah they are threatening....but the hatred from humanity never ends and can come from any origin. So I would say humanity.

@cattlebattle: I agree with that in spirit. I would say they fight popular perception, more than, say, actual humans, but sure.

Themselves. XD Srsly. <.<

X-Men's greatest enemy has always been the mutants themselves. Sooner or later they'll always find something to fight about amongst each other.

@Edamame: she'd win.

In the classic sense, Magneto. His goal is similar enough but different enough to the X-Men to both impede their progress and fuel the ammo that can be used against them by the majority. He is even more dangerous when it becomes harder to distinguish him from the X-Men. X-Men also must face the possibility of moving towards Magnetos methods and ideology as well, and although there is plenty of room to do that without actually becoming Magneto, that line (or space) can get a bit blurry. Magneto is also very charismatic and can be very inspirational. He also isn't always a cartoonish villain or a villain stuck with old world philosophies which inherently isolates himself from the modern world.

I think it depends on your definition of "dangerous"

you could say "dangerous" as the most powerful...if that were the case then I would say someone like Onslaught, Apocalypse, or Belasco

or "dangerous" could mean other things....Stryker has caused all kinds of huge problems for the X-men and has killed more than a few of them...same goes for Bastion

Juggybug is pretty freakin' dangerous.

Right now Scott Summers, guys got a screw loose

Greg land

I'm going to go with Legion off his meds.

@DH69 said:

Greg land

GREG LAND!!! wahahha! Up there with The Schumacher being Batman's greatest villain

@DH69: ohhhhhhh snap!

@danhimself said:

I think it depends on your definition of "dangerous"

you could say "dangerous" as the most powerful...if that were the case then I would say someone like Onslaught, Apocalypse, or Belasco

or "dangerous" could mean other things....Stryker has caused all kinds of huge problems for the X-men and has killed more than a few of them...same goes for Bastion

Hahaha! Belasco!

but, yeah, that's why I picked Bastion over Sinister.

Dangerous in the amount of destruction they've done? Dark Phoenix, easily.

Putting serious thought into this, I'd go with Magneto for a couple reasons.

1. A full power, he could destroy the planet quite easily.

2. Leadership/Influence- He's been the leader of a bulk of the mutant race on more than one occasion on 616 Earth. He's the go to guy when the fighting starts.

3. Conviction - He goes down whatever path he walks and follows through on his decisions no matter what because he believes in what he does.

4. Go read Magneto: Not a Hero. Namely for when he mentions his thoughts on good and evil. Just that quote (shivers)

Just gonna quote this for the word conviction.

btw, found the quote

boom bitches

I think Magneto is too tame. He does have potential to be the most dangerous, but he usually uses restraint. He does have some more brutal moments, but some of them seem almost out of character.

Dark Phoenix blew up a solar system. You don't get very much more dangerous than that. A distant second would probably be a toss up between Magneto at his worst and Onslaught.

Strife, Scarlet Witch, and the Inhumans all deserve a honorable mention for bringing mutants to the brink of extinction.

Dark Phoenix

Onslaught

Proteus

Legion

Bendis.

Axel Alonso and Tom Brevoort

*shudders*

+1 - she is like Professor X's Lex Luthor.

Bendis.

It is definitely Bendis outside of the covers IRL. I do not think he likes the X-Men TBH - just a few individual members.

@rubear: ^this^

Fox having the movie rights.

Dark Phoenix.

Scarlet Witch.

Scarlet Witch, Cassandra Nova, Stryfe and Onslaught

Onslaught. Red and otherwise

Dark phoenix

Fox

Marvel Comics

Mr Sininster

dark phoenix, way to obvious