Is there such a person as a "berserker"?

It seems as though every person is motivated by a set of desires and emotions. In the movie "fight club", Tyler Durden is able to do whatever he wants without contemplating the consequences as he has no desires nor any emotional connection to anything. However, surely his lack of emotions is still an emotion in of itself which gives him a reason to do the things he does.<br><br>The perfection of a "berserker" would be someone who is able to do whatever they want without any form of contemplation whatsoever, as soon as an idea is conceived it would be executed with no emotions or desires motivating them. This would surely mean that there would be no reason for them to do anything, as there would be no desires to fulfill and no emotions to listen to. I guess what I'm asking is, would it ever really be possible for such a person to exist?