Christian is a synonym of Kind. Kind is related to Soft. Soft is related to Sheep. Sheep is related to Creature. 
Medium is a type of Substance. Medium is related to Size. Size is related to Mass. Mass is related to Density. 
Christian <--Synonym--> Kind <--RelatedTo--> Soft <--RelatedTo--> Sheep <--RelatedTo--> Creature 
Substance <--IsA-- Medium <--RelatedTo--> Size <--RelatedTo--> Mass <--RelatedTo--> Density 