Board Thread:Naruto Discussions/@comment-24347194-20150211225344/@comment-26302001-20150402203938

It's not his full potential, because he didn't have Kurama until after he was already about to die, after he did the death god ritual, he does have sage mode BUT as he himself said he does not use it for battle. Minato would only get his powers he had pre-death god ritual because Kurama he had as an Edo Tensei.