Desire would make you want to Buy. Desire is related to Sexual. Sexual is a synonym of Intimate. 
Changing is related to Painter. Painter is related to Person. Reader is a type of Person. Reader is the opposite of Author. 
Buy <--CausesDesire-- Desire <--RelatedTo--> Sexual <--Synonym--> Intimate 
Changing <--RelatedTo--> Painter <--RelatedTo--> Person <--IsA-- Reader <--Antonym--> Author 