Finnick assumes the man must be speaking of the island residents in his 'all of us' though it's the first he's heard of this Aslan.

He glances at the man's hand and, smiling, takes it in a warm shake. "Finnick," he says. "The first." Then, glancing down at the stretch of sand next to Caspian, adds," Do you mind if I sit with you for awhile?"