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CEO, BS Comics
Would take over the world.
Easily.
Iceman - Use of powers covert, powerful enough to take over the world quickly.
Superman - Use of powers obvious, but powerful enough to take over the world quickly.
Magneto - Use of powers covert, powerful enough to take over the world quickly.
Any of these three could launch an all out assault and likely win.
With some effort.
Green Lantern - Use of powers obvious, but powerful enough to take over the world.
Storm - Use of powers covert, powerful enough to take over the world.
Invisible Woman - Use of powers covert, powerful enough to take over the world.
Mystique - Use of powers covert, devious enough to take over the world.
Would not be able to take over the world.
All three's use of power is obvious and none have sufficient power to take over the world.
Carnage
Iron Man
Colossus
Mystique
There is nothing we have at present to detect her easily. Biometrics are useless on her. She has been impersonating people for a century and more, she is manipulative enough to not draw attention or suspicion. She gains an immense fortune by defrauding banks while impersonating billionaires. She uses the countries own armies against them by impersonating their leaders.
Invisible Woman
She is invisible. Her force shields have withstood incredible amounts of damage (and apparently have never fallen?). Also Ultimate Invisible Woman might have a better chance as she seems just as powerful and is a bona fide genius too. IW walks into the G8 leader's summit unnoticed. All the leaders suddenly suffer cerebrovascular accidents.
Storm
Her mood affects the weather around her sub/unconsciously, it would not strain her to create powerful and destructive phenomena. Once she sows the seeds of a massive meteorological phenomenon it will run its course. The phenomena may appear suddenly and be anomalous to data, but the pattern of manipulation she uses to create her phenomena would conform to what normally happens when a hurricane or rain or whatever is produced. They are more likely to question why their data didn't conform to what happened than vice versa. She can devastate governments and economies without bringing attention to herself because there are no tangible links between her and what she creates, besides who would suspect a human of controlling the weather. When the world is weakened and anarchous she can make her move.