I don’t know how UEFN codes is but there is a logical solution to this. Every item has unique ID for itself. When character gets any item, check if it’s that the item you want. For example X Item must change the class, ID is 34. Make a if node, check if id is 34. If so; Change the class, And when character drops any item, check the item same way, if the item ID 34; switch to class 1.