[metroidreborn]

Well, the way I see it, if LeChuck really knew the power that Elaine had, he would want to make sure no one knows about it, especially Guybrush. If Guybrush were to find out, he may be able to use it to destroy LeChuck for good. So LeChuck refused to answer the question and even said he did not know what it was to insure Guybrush never finds out, at least not through the method of asking him.