According to Franken Fran's plot, the painter in EP8 was attacked by a mysterious face dog, which caused him to lose his left hand. This face dog is very frightened, because it seems to be very hostile and aggressive to human beings, and its behavior is very strange, unlike ordinary animals.

Before the painter was attacked, Fran injected him with a mysterious serum, which is said to stimulate people's potential. However, this serum also seems to be related to the appearance of this human face dog. During the investigation, Fran found that this human face dog may be a creature mutated from some kind of serum, which was developed by her.

Therefore, the reason why the painter was attacked may be because this human face dog has some reaction to the serum developed by Fran, or because it is sensitive to the smell of the serum on the painter. In a word, this incident is related to the serum developed by Fran, and the appearance and attack of human face dogs are also part of this incident.