The hard-working secretary in the novel

A tool man becomes a heartthrob in seconds, Yan Dun transmigrates into a hard-working secretary in Mr. Ba's novel. He originally thought his job was to be a tool man, watching the things that Mary Su and Mr. Ba had to say, but... the situation changed... It's getting more and more wrong.Why does the role that originally belonged to Mary Sue seem to be silently transferred to him?Isn't he a tool man?Why does it seem like he has become a heartthrob?When the situation became more and more strange, Yan Dun couldn't help reporting the abnormal Yan Dun: Is this a BUG?Customer Service: Dear, have you ever taken a shit after crossing?Ever farted?Yan Dun: ...No.Customer service: Oh, then you are the heartthrob protagonist Shou. 1V1, HECP: Kishizao X Yandun