you can find the z core zg from a gojulas i found mine in the ruins where you find alster
i think it was the 3rd sub level

before you start a new game just press:right,up,up,up,down.up,left,up,right,down,
up,down,right,up..
And u will unlocked "hyper saberlion zoid"
Hp: 500
Ep: 100

the best attack of this zoid is "Giga Blade"
attack: 500