War Counselor Iji, also known as Master Iji the Blacksmith, is an NPC that can be found in Elden Ring's world. He is an expert in Somber Smithing Stones and can upgrade your weapons.
Iji is an extremely important character to the Questline of Ranni the Witch, who is trying to betray the Golden Order and start a new era in The Lands Between. He is a major player in Ranni's rise and is a close advisor to her, serving as a "War Counselor" until the end of her quest line when he is killed by Black Knife Assassins under the orders of the Two Fingers.
He is located in Caria Manor, a property in the northernmost Liurnia of the Lakes district of Elden Ring. He's situated southwest of the Manor and is near the Graceful Road that connects to the Manor, making him fairly easy to spot.
When you first meet him, he warns you about a powerful spell that surrounds the Caria Manor and asks you to avoid it. However, you will later discover that he is actually in service of the Lunar Princess Ranni, and that he and all the other servants of her are loyal to her and her cause.
In the end, Ranni manages to fulfill her purpose and escape The Lands Between, and Iji - along with many of her other servants - is left behind in the Lands Between. Eventually, the vengeance of the Two Fingers comes for them and they are all killed.