likely to do something suddenly, without considering the results of your actions
impetuous
isn't warm and friendly, instead being distant and reserved.
aloof
kind and helpful; having a desire to do good
benevolent
to follow a set of rules no matter what.
dogmatic
having or containing a lot of knowledge that is known by very few people
erudite
believing that people are motivated purely by self-interest; distrustful of human sincerity or integrity.
cynical
behaving in a kind and pleasant way
affable
changing mood or behaviour suddenly and unexpectedly
capricious
fond of the company of others; sociable
gregarious
an individual that acts in a hostile manner eager to fight, such as engaging in combat.
belligerent
showing no real interest or effort:
indolent