Evi was one of five kings of Midian who were killed in a battle against Israel under the leadership of Moses (Numbers 31:8). God apparently told Moses to fight against Midian because the Midianites had led the Israelites to practice pagan religions. Joshua 13:21 calls Evi a prince of Sihon, the Midianite king.
Evi
From Tyndale Bible Dictionary, adapted by Mission Mutual. CC BY-SA 4.0.