Cyberpunk Echoes

Kai, a mercenary at the bottom of Night City, was drilled into the neural interface by something that shouldn't exist during a commission. The ICE breaks in seconds, predicts ballistics, and marks escape routes in advance - it doesn't talk to him, but every time it takes action, it is so precise that it is unlike anything in this world. The price is nosebleeds, cramps, and nerve pathways being burned out one by one. Kai only knows three things: it's not an AI, it could have overridden his consciousness but it didn't, and it doesn't have much computing power left. When Arasaka, Military Technology, and Kang Tao simultaneously start hunting an "unusually efficient operator" - Kai must decide whether the quiet existence in his mind is a weapon or the only thing he should not lose in his life.