The Apothecary advances as a savant first, deepening the medicae craft that keeps the line whole, and reaches only secondarily into ferocity, leadership, shooting and the House's own discipline. His growth serves the gang's endurance rather than his own tally of kills.
The Captain has the broadest advancement in the House, drawing freely on brawn, leadership, savantry, shooting and the Signature discipline, with close combat and ferocity within slower reach. He grows into the complete anchor of the line — commander, marksman and immovable point all at once.
The Centurion advances toward raw power and gunnery, its Primary access built on brawn, shooting and the House discipline, with combat, ferocity and savantry in slower reach. It learns to hold and fire better than it ever learns to manoeuvre.
The Chaplain advances on ferocity and leadership, the twin engines of the line's resolve, reaching only secondarily into brawn, close combat, shooting and the House discipline. He grows into the will that keeps the wall standing when the guns alone would not.
The Devastator advances as a gunner: brawn to hold the heavy weapon steady, shooting to place its fire, and the Signature discipline that rewards a held position, with ferocity and savantry in slower reach. Its whole growth bends toward standing still and hitting harder.
The Dreadnought advances on brawn and shooting, the strengths of an interred hero built to anchor a lane and hold it, with close combat and ferocity in slower reach. It grows steadier and deadlier where it stands.
The Heavy Intercessor advances toward the weight and gunnery of the siege trooper, its Primary access built on brawn, shooting and the House discipline, with combat, ferocity and savantry in slower reach. It grows into a wall that is harder to move and deadlier to approach.
The Librarian advances as a savant first, sharpening the disciplined mind that carries his powers. Secondarily he reaches across cunning, ferocity, leadership, shooting and the House discipline. His growth runs inward — toward the witch-sight that is his true weapon. The Librarius Discipline is his to deepen as a Primary access, with the universal Smite open to him as a Secondary.
The Lieutenant advances broadly. He draws freely on brawn, leadership, shooting and the Signature discipline, with combat, ferocity and savantry in slower reach. He grows into a second anchor for the line — ready to hold whatever stretch of the wall the Captain does not.
The line Marine advances first as a shooter and a keeper of the House discipline, with brawn, combat, ferocity and savantry all within slower reach. He becomes better at exactly the thing the gunline asks of him: holding still and firing true.
The Scout advances as a forward skirmisher. He draws freely on agility, cunning and shooting, screening the line and holding the ground ahead of it. Savantry and the House discipline come only later — the neophyte growing toward the wall he will one day stand in.
The Techmarine advances as a savant and a gunner, its Primary access built on brawn, savantry and shooting — the trades of the smith who raises the firebase. Close combat and the House discipline come more slowly, as the emplacements he sets do the heavy work for him.