Liam shapes by instinct. He shaped the room with all the furniture on one leg inside of the cloudwall, where Cole slept. Liam had great talent at a young age as Declan says, but they had different shaping styles. Liam was a young, powerful shaper in search of a teacher. He had been taken as a slave and used his shaping as an escape. Declan told Mira, Jace, Twitch, and Cole that Liam had great talent at a young age.
Liam became a slave when his "parents" sold him, but he never knew his real parents. His real parents died in a riot. Liam's "parents" did not like his shaping, and told him to hide it, when he disobeyed, they sold him into slavery. Twenty years later after Liam escaped, he was looking for Declan, and found his way to the Cloudwall by going through Boomerang Forest.
Liam is described with boyish features and mischievous eyes. There is no given age but appears to be about twenty. He is seen using a disc hovering. He wore a fuzzy brown jack and alligator-skin boots. Liam also carried what looked like silver salt shakers in each hand.
Declan says that Liam is gifted, but lacks seriousness as well as focus. He claims to be in certain places just because he's bored.