The "to solve" ability of Case of the Gorgon's Kiss looks at what type the cards are after they move to the graveyard to determine whether the ability should trigger, regardless of any types they may have had before they were in the graveyard. For example, a creature card that has become a noncreature permanent will count toward the ability's condition when it's put into a graveyard. By contrast, a noncreature card that has become a creature on the battlefield will not count toward the ability's condition when it's put into a graveyard.