A way to level up
The message had come as a surprise for him; the system had said nothing about a cap before, and now suddenly this message had appeared. But Quinn did remember that the system often said that it didn't create the system himself. So there were some things even he didn't know, and this could have just been one of them.
Still, not wanting to waste any more time, Quinn decided to continue onward to the next set of blood packs. Even if he had maxed out on one, it didn't mean he had maxed out on the others.
After drinking what they had of type B blood, the same message appeared once again.
[40 Agility points reached.]
Moving onward, Quinn continued in this fashion, taking a small amount of blood from each one until, eventually, all of his stats had reached the top.
[Strength 40]
[Agility 40]
[Stamina 40]
[Charm 40]