What is the counterpart theodicy? what is one problem with the view?

A theodicy for some given fact about evil is an explanation for why God would have an all-things-considered sufficient reason to allow that evil. The counterpart theodicy relies on a metaphysical claim about existence. We cannot know what "good" is unless there is "evil" to contrast it with. (1) Doesn't justify all kinds of evil (Do we need genocide to know what goodness is?), (2) Doesn't justify the amount of evil (Do we need so much killing/theft to know what goodness is?), (3) God can know good/evil prior to creation/evil.