Missionary is related to Position. Position is related to Captain. Captain is related to Vessel. 
Nasty is the opposite of Divine. Divine is a synonym of Beautiful. Beautiful is the opposite of Weak. Weak is the opposite of Healthy. 
Missionary <--RelatedTo--> Position <--RelatedTo--> Captain <--RelatedTo--> Vessel 
Nasty <--Antonym--> Divine <--Synonym--> Beautiful <--Antonym--> Weak <--Antonym--> Healthy 