Indigenous is a synonym of Native. Native is related to Indian. Indian is related to Rice. Rice is related to Field. 
Charge is related to War. you are likely to find Enemy in/at/on War. Enemy is related to Rival. 
Indigenous <--Synonym--> Native <--RelatedTo--> Indian <--RelatedTo--> Rice <--RelatedTo--> Field 
Charge <--RelatedTo--> War <--AtLocation-- Enemy <--RelatedTo--> Rival 