In 1967 with the start of the Nigerian Civil War Eutuk, a native of Ibibio, joined the Biafran Army and quickly rose in ranks. Eutuk is said to have fought at most of the large-scale battles during the war. When Eutuk was made Colonel he was out into command of the Biafran 16th Division to defend the city of Owerri from the oncoming Nigerian Army. When General Benjamin Adekunle decided to invade Aba instead of Owerri he was relieved and decided to stay back and let Major Timothy Onwuatuegwu handle the Nigerians. After separate battle at Aba and Umuahia Eutuk did not expect the Nigerian Army to arrive. On September 17, 1968 General Benjamin Adekunle attacked Owerri. Eutuk and his men overpowered Adekunle's troops and forced them to flee to Oguta but when Eutuk arrived in Oguta he was met with heavy firepower from Adekunle's troops. Eutuk fled to Umuahia leaving Owerri open to occupation. Immediately after the occupation of Owerri Biafran President Odumegwu Ojukwu ordered Eutuk and Major Onwuatuegwu to invade and retake Owerri. After 7 months of heavy fighting Eutuk is able to recapture Owerri. After Owerri was retaken Ojukwu sent Eutuk and Onwuatuegwu to Umuahia for defense. On March 22, 1969 Nigerian General Mohammed Shuwa invaded modern-day Abia State with 8,500 men. A large force of MiG-17's bombed the towns of Uzuakoli and Arochukwu but did not damage any Biafran defenses. On April 22 Shuwa was able to break through Onwuatuegwu's line of defense and was able to take Umuahia. E.A. Eutuk decided to invade the city and after four hours of Nigerian occupation, Eutuk was able to retake the city. Nine months later, when Biafra surrendered to Nigeria, Eutuk was last seen at a party in Lagos in early 1970.
He has not been seen since and is thought to be dead.