Jiro has blue-gray skin with a faint sheen like wet stone, dark teal hair that hangs in uneven cords around his face, and pale silver eyes with no visible pupils. Thin lines resembling river channels trace his forearms and throat. He is lean, broad-shouldered, and carries himself with the balanced stillness of a practiced duelist. His Steel Keeper uniform has been altered with waterproof stitching, weighted hems, and a strip of red cloth tied around his sword wrist.

Jiro is observant, dryly humorous, and more patient than he first appears. He prefers to let arrogant people reveal themselves through careless speech. Around trusted companions he is quietly generous, repairing gear without being asked and remembering exactly how each person takes their tea. He dislikes grand speeches, public heroics, and anyone who treats soldiers as interchangeable parts.

Jiro Slade was raised in a harbor district where the water genasi families lived between the salt warehouses and the old breakwater. His mother repaired navigation instruments, while his father served aboard a patrol cutter and taught him that a sword was less important than knowing where the next wave would come from. Jiro learned quickly. He became an excellent swordsman by fighting in cramped dockside alleys, on pitching decks, and in formal drills where his strange footwork made opponents misjudge his reach and timing. He recently joined the Steel Keepers after stopping a smuggling attempt involving sealed iron cylinders recovered from a reef shrine. The cylinders bore the insignia of the Keepers, but the officers who claimed them were not listed in any surviving roster. Since then, Jiro has found coded references to drowned prisoners, deliberate changes to the island's tide charts, and a sealed chamber beneath the Steel Keepers' own fortress. He has told no one the full truth. Some of the people above him may be involved, and the evidence suggests the island's troubling secrets are connected to something moving beneath the surrounding water.