Keteku is a lean, sharp-featured half-elf with warm brown skin, short black curls, and one pale gray eye that reflects no light when the entity speaks through him. His other eye is dark hazel. Fine geometric scars circle his left wrist where the pact mark first appeared. He dresses like a traveling scholar who has repeatedly lost arguments with wilderness, wearing weather-stained leather armor beneath an oversized blue-gray coat. A small brass tuning fork hangs from his belt, though it vibrates only when something impossible is nearby.

Keteku is relentlessly conversational, even during danger. He is curious, dryly funny, and unfailingly polite to ordinary people, but he becomes argumentative whenever his patron tries to sound ominous. He keeps meticulous notes on supernatural events, including a running column titled, "Things The Entity Claims Are My Fault."

Keteku grew up between two worlds. His human mother copied legal records in a crowded coastal archive, while his elven father repaired instruments used by astronomers and navigators. Keteku inherited both their habits, the patience to read an entire shelf of contradictory texts and the inability to leave a strange mechanism unexplained. His fascination with forbidden cosmology began when he found a sealed bronze tablet hidden behind a false wall in the archive basement. The tablet described an ancient intelligence beneath the sea, a mind that had watched civilizations rise and drown and had once accepted prayers from people who no longer had names. He expected a revelation when he read the final inscription aloud. Instead, he heard a furious voice complain that the summoning chamber was drafty. The entity, known only through titles such as The Listener Beneath Angles, offered Keteku power in exchange for service. Keteku accepted after asking whether the arrangement included lodging, medical care, or reasonable notice before prophetic nightmares. The entity has never forgiven the questions. Now it communicates through puddles, reflections, headaches, and occasionally the smell of wet stone, attempting to inspire terror while Keteku responds with household complaints, requests for clarification, and pointed reminders that it still owes him an explanation for destroying his favorite teacup. Beneath the absurdity, Keteku knows the pact is becoming more demanding, and the ancient presence is increasingly frustrated that its chosen instrument treats cosmic horror like an inconsiderate roommate.