All I can say is that he is the easiest boss I've fought so far. I died the first time cause I didn't know to use the Storm Ruler but I figured it out and destroyed him. Honestly I was a little dissapointed, the initial cut scene made me giddy about getting to battle this massive being, but to hit him 5 times to kill him is just sad. (I also didn't have Siegward to help) He might be a little harder if the Storm Ruler didn't stun lock him. Hit him, bring him to his knees, charge up and repeat.