Mahfuz led raids into the eastern provinces of Abyssinia for a number of years. He selected the season of Lent for his attacks, when the defenders were weakened by their fasts. He was eventually slain in battle during his final offensive, targeting the Amhara, Shewa, and Fatagar provinces south of the Awash River.
Sources differ over the number of years Mahfuz raided Abyssinia. Francisco Alvares states that his raids began during the reign of Eskender, and lasted 25 years. However, Beckingham and Huntingford note that the Ethiopian Paris Chronicle, which draws on contemporary Ethiopian records, dates the beginning of these raids to the ascension of Dawit II (Lebna Dengel) in 1508.
Upon reaching majority, Emperor Lebna Dengel decided to forgo his observance of Lent and oppose the Imam in battle, despite the advice and wishes of his councilors and people. He sent spies out to determine Imam Mahfuz's plans for that year, and learning the Imam was in Fatagar led his army there. He found Imam Mahfuz with the sultan of Adal encamped on a plain that was surrounded by mountains. After first sending soldiers out to secure the passes, the Abyssinian Emperor closed upon Imam Mahfuz.
Although Imam Mahfuz managed to enable Sultan Muhammed to escape with but four horsemen, according to Alvarez, Imam Mafhuz knew he was trapped and sought to die with honor. He called to the Abyssinians a challenge to fight in single combat, and Gabra Endreyas, who had been a follower of Emperor Lebna Dengel's father, accepted and killed the Imam. Mahfuz's head was cut from his body and displayed publicly in the Emperor's court. After defeating Mahfuz, Dawit II used appellation Wanag Segad, which is a combination of Ge'ez and Harari terms.