Virtual is the opposite of Legal. Legal is a synonym of Legitimate. Legitimate is the opposite of Sharp. Sharp is the opposite of Honest. 
Associate is a synonym of Join. Join is related to Union. 
Virtual <--Antonym--> Legal <--Synonym--> Legitimate <--Antonym--> Sharp <--Antonym--> Honest 
Associate <--Synonym--> Join <--RelatedTo--> Union 