May is related to Must. Must is related to Order. Warn is a type of Order. Threaten is a type of Warn. 
Costume is related to Habit. Habit is related to Group. Group is related to Suite. Suite is related to People. 
May <--RelatedTo--> Must <--RelatedTo--> Order <--IsA-- Warn <--IsA-- Threaten 
Costume <--RelatedTo--> Habit <--RelatedTo--> Group <--RelatedTo--> Suite <--RelatedTo--> People 