Picked up a Time Traveler

During an assassination mission, he picked up a person who claimed to be a time traveler. Well, there might be something wrong with this person's brain. However, in the subsequent interactions, he felt there was a problem. What is a steam engine, what is a gun, and what is a train? You said you want to promote the change of this dynasty? Is that all it takes? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.