Age: 21 years, 8 months
Place of Birth:
Killian played underage football with Everton AFC before joining Cobh Ramblers' U17 squad for the 2015 and 2016 seasons. At the end of 2016 he returned to Everton where he played in the team that competed in the 2017 FAI Cup.
In February 2021, Killian signed for Cobh Ramblers from College Corinthians.