Hostile is a synonym of Sharp. Sharp is related to Bitter. Bitter is related to Dark. 
Activist is a type of Person. Person is related to Brother. Brother is related to Face. 
Hostile <--Synonym--> Sharp <--RelatedTo--> Bitter <--RelatedTo--> Dark 
Activist --IsA--> Person <--RelatedTo--> Brother <--RelatedTo--> Face 