Blade is related to Weapon. Weapon is related to Harm. Harm is the opposite of Heal. Therapist can be used for Heal. 
Intend is a synonym of Mean. Mean is a synonym of Cause. Producer is a type of Cause. 
Blade <--RelatedTo--> Weapon <--RelatedTo--> Harm <--Antonym--> Heal <--UsedFor-- Therapist 
Intend <--Synonym--> Mean <--Synonym--> Cause <--IsA-- Producer 