Challenge is a type of Invite. Invite is related to Join. 
Eligible is similar to Suitable. Suitable is a synonym of Fit. Survive have Fit. Survive is a synonym of Endure. 
Challenge --IsA--> Invite <--RelatedTo--> Join 
Eligible <--SimilarTo--> Suitable <--Synonym--> Fit <--HasA-- Survive <--Synonym--> Endure 