Kethrik is a lean, copper-skinned high elf with straight ash-brown hair cut to the jaw and pale gray eyes flecked with green. His long fingers are stained with ink and salt, and the tips of his ears are notched from an old rigging accident. He dresses in a weathered navy coat over simple scholar's robes, with a spellbook sealed in oiled leather and a brass compass hanging at his throat.

Kethrik is observant, patient, and quietly compassionate. He treats every ship, ruin, and weather pattern as a puzzle worthy of study, but he is more comfortable with facts than with emotional conversations. He has a dry sense of humor, a deep respect for competent sailors, and a habit of collecting small pieces of unusual glass or sea-smoothed metal.

Kethrik Arveth was raised among the tide-houses of an elven harbor where ships were built according to star charts and old mathematical songs. He showed little interest in swordplay or courtly music, but he could spend hours studying knots, currents, and the strange blue sparks that sometimes danced across the mast during storms. An aging ship's mage recognized the pattern in those sparks and took Kethrik on as an apprentice, teaching him that magic was not merely inherited wisdom, but a discipline of careful observation and exact words. His apprenticeship ended abruptly when a coastal expedition vanished beneath a calm, moonlit sea. Kethrik survived by clinging to a broken spar, but his master's spellbook was lost with the ship. Since then, he has worked passage from port to port, combining sailor's instincts with unfinished arcane study. He believes the wreck was not an accident, and he now searches for the vessel's lost logbook, convinced that its final entries contain a warning about a power moving beneath the sea.