A Stalwart Blade is a large, humanoid Heartless covered from head to toe in faded red and white armor. The armor on its legs sport white spikes and steel blue highlights. Its helmet sports two short, white spikes and a long, twisted, black antenna. A small opening in the front just barely exposes the Stalwart Blade's black face and glowing yellow eyes. Its most notable features are the orange, interweaving blades in place of each of its hands. It has two Heartless emblems, one on each of its shoulder pauldrons.
The Stalwart Blade's name reflects its resistance to magic and its skill with defense, as "stalwart" means "firmly built". It also references the blades on the Heartless's arms. Its Japanese name, "Strength Blade", references its great power.
Like most arm-blade knights, the Stalwart Blade attacks with sliding thrusts, spin attacks, and drop bomb attacks. Like the others, it becomes stunned and dizzy after its own attempts. Dodge its attacks, then counter during its malaise. It recovers all too quickly, so be ready to jump or roll away. Hit it with Aero spells to stun it for longer periods of time, creating more chances to hit it.