The reason has never been made clear, but all Gorz prints are
like that. Yes, limited edition cards have always had gold
stickers, but for some reason, Gorz was given a silver one.
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Yes. Like Cyber Dragon, Gorz 'can' special summon himself with
his effect, but he is not a 'special summon only' monster, he can
be tribute summoned with two tributes, if you want.