Killian Dain is a Northern Irish professional wrestler, whose real name is Damian Mackle. He is best known for his time in WWE, particularly on the NXT brand, and for his current work on the independent circuit under the name Big Damo.
Standing at approximately 6 ft 4 in and 322 lbs, Dain is recognized for his imposing size and power-based style, earning him the nickname “The Beast of Belfast.”
Mackle began his professional wrestling career in 2005, training in Scotland under coaches including Robbie Brookside and Fergal Devitt (Finn Bálor).
He initially competed under names such as Damian O’Connor and Big Damo across the UK and European independent circuit, building experience through tag team and singles competition. His early career included multiple regional championships and steady progression across promotions.
He gained major recognition in WWE as a member of the faction SAnitY, alongside Eric Young, Alexander Wolfe, and Nikki Cross.
Following his WWE departure in 2021, he returned to the independent scene as Big Damo, continuing to compete in major UK promotions and winning additional championships.
His ICW title win in 2016 marked a major milestone, making him the first Northern Irish-born ICW World Champion.
Killian Dain is defined by a power-heavy, hybrid wrestling style, combining size, agility, and striking.
Unlike traditional heavyweights, Dain blends size with mobility, making him effective in fast-paced and chaotic match environments.
Dain is widely recognized for his role in WWE’s NXT era, particularly as part of SAnitY, one of the more distinctive factions of that period.
Killian Dain is a veteran Northern Irish professional wrestler known for his size, power, and versatility. Rising through the European independent scene to WWE prominence as part of SAnitY, he later returned to the independent circuit where he continues to compete as Big Damo.
With championship success across multiple promotions and a style that blends strength with agility, Dain remains a prominent figure in both British and international professional wrestling.
United Kingdom
