Damian Mackle is an Irish professional wrestler. He is best known for his time in WWE, where he performed under the ring name Killian Dain and since his departure from WWE he has reverted back to his ring name on the independent circuit Big Damo. That ring name Big Damo is derived from his first ring name, Damian O'Connor. Prior to joining WWE, he won the ICW World Heavyweight Championship while wrestling for Insane Championship Wrestling. He also wrestled for numerous promotions on the British ...