Rice is the opposite of Wheat. Wheat is related to Crop. Crop is related to Grass. Grass is a type of Unfold. 
Powerful is related to King. King can be Royal. 
Rice <--Antonym--> Wheat <--RelatedTo--> Crop <--RelatedTo--> Grass --IsA--> Unfold 
Powerful <--RelatedTo--> King --HasProperty--> Royal 