hsrob on 07 January 2010
Here is a video walkthrough. http://www.youtube.com/watch?v=RWXOTcyRcEg, if you want to see exactly what to do.
However it sounds like all you are failing to do is go into hypermode when his core is exposed. He has several different attack patters but they all end with him sitting there showing a glowing, exposed core. You just need to hold that little + button and go nuts.
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