Mercury in Aquarius:
Unconventional in self-expression, Mercury in Aquarius natives enjoy breaking the rules. They are not necessarily loud or flamboyant people, but they often have a quiet way of stirring others up. These natives delight in exposing what they deem biases in others’ way of thinking.
Very quick to contradict others, and to offer a different perspective, these natives enjoy intellectual debates. They’re very quick and alert, and their powers of observation are particularly strong. They usually “win” debates. In fact, they’re very interested in scoring intellectual points, which can be maddening to others at times!
Aquarius is an air sign, which is detached and intellectual by nature. It is also a fixed sign, so people born under Mercury in Aquarius often have an intellectual “agenda”. They are even given to forcing their ideas on others. This apparent intellectual superiority complex can intimidate others at times.
On the other hand, Mercury in Aquarius people can make for delightful company. They usually have something interesting to say, and their perspective on issues can be delightfully unusual, quirky, and surprisingly insightful.
These individuals have unusual study habits. They generally are resistant to following schedules, even if they have a Capricorn Sun–and perhaps particularly so with a Pisces Sun sign. Although they are often surprisingly organized, their sense of order may not be entirely understandable to others.
These natives are often attracted to scientific and/or metaphysical pursuits. Anything that promises progress and advancement for mankind has special appeal. Their sense of humour is often well-developed and unique. Practical jokes and anything that shocks and stirs up others are especially appreciated by Mercury in Aquarius people. (Source).