Gun is related to Deadly. Deadly is a synonym of Fatal. Fatal is a synonym of Inevitable. 
Ease is a synonym of Still. Still is the opposite of Dance. Dance is related to Drill. 
Gun <--RelatedTo--> Deadly <--Synonym--> Fatal <--Synonym--> Inevitable 
Ease <--Synonym--> Still <--Antonym--> Dance <--RelatedTo--> Drill 