Weakness is the opposite of Energy. Energy is the opposite of Fatigue. Fatigue is similar to Duty. 
Energy is related to Emerge. Shell is a type of Emerge. Shell is related to Defense. Defense is a synonym of Denial. 
Weakness <--Antonym--> Energy <--Antonym--> Fatigue <--SimilarTo--> Duty 
Energy <--RelatedTo--> Emerge <--IsA-- Shell <--RelatedTo--> Defense <--Synonym--> Denial 