A chivalrous thief from Renais, a childhood friend of Neimi who once managed to steal Eirika's bracelet, and later infiltrated a bandit hideout to find Neimi's lost handmirror, stolen by bandits. He is rather snide and arrogant, but genuinely cares for Neimi. He is also quite proud of his thieving prowess.
Possible Endings
Normal ending: He politely refused an invitation to become a spy for Renais, returning instead to his hometown. He spent the rest of his days as a chivalrous rogue helping those in need from the shadows.
Colm/Neimi ending: The childhood friends became lovers first, then husband and wife. Worried for Neimi's well-being, Colm gave up his adventurer's ways. Neimi passed on her grandfather's skill in archery to her own son and daughter.
Colm can form a support with Neimi, Marisa, Rennac, Moulder, or Kyle.