Darksiders 2 is one of my all time favorite games. Fighting the first major boss, The Guardian was one of the most epic and amazing moments I have ever experienced in a game. Jesper Kyd hits it out of the park with the powerful theme that goes with this fight. Simply fantastic. Make sure to summon Death's mighty steed, Despair. You are going to need to cover a lot of ground rather quickly. Once the Guardian slams his massive hammer into the ground, pull out your pistol and aim for his arm. Once it explodes you need to quickly get to the rubble and climb towards the life gem that is animating the Guardian and destroy it. The other arm is a bit tricky though, seeing as you need him to get the giant Cannon ball he shoots to hit him. Nothing a little line of sighting can't fix though.