My guess: father really wants a S grade son. In theory the twins were supposed to be S, but they had a premature awakening. So he is trying to re-awaken him as a S rank? The MC suddenly became a S guide, so I'm sure dad wants to know why and how. That brings us to a very important question: will he publish a paper and have it peer reviewed? (And he petted the lamb, so I want to believe he is not bad BAD. At least he should have good ethics!)
Do evil scientists submit their papers for peer review? I like your idea about the power boost. Hopefully he got his son's consent prior to experimenting on him.
My guess: father really wants a S grade son. In theory the twins were supposed to be S, but they had a premature awakening. So he is trying to re-awaken him as a S rank? The MC suddenly became a S guide, so I'm sure dad wants to know why and how. That brings us to a very important question: will he publish a paper and have it peer reviewed?
(And he petted the lamb, so I want to believe he is not bad BAD. At least he should have good ethics!)