How do you beat the giant silver robot in the beginning of kingdom hearts 2?

depends on your mode.for beginner and normal mode,just follow all of the reaction(triangle) commands and when it's down,MASH the attack button;for proud mode though,you must be a bit more careful.it will have more hp and attack power,so you sometimes will have to go on the defensive side(which is why i always choose the shield :) )anywho,you'll need to master the Reversal command to survive;it starts to unleash spiky talis everywhere and it makes it hard to reach the Nobody;otherwise,if you just run into it,you'll end up hurt instead.