Well the reason I fight is for the adrenaline rush that I get since I am naturally hyper and I love the feel of not knowing if I'm going to live or die.

Also because of pride of knowing that I did better then the person I'm fighting when ever I see the kill message pop up on the screen showing I am the victor.

Then the "honor" of getting a victory for your faction when you help to achieve a successful raid on your enemy's.

There is a little bit more but I don't like typing on my phone.