I have a theory that it's probably Hero/Alice's dad. But that raises the question why he sent his weak ass son first before his OP daughter.
Well, let's make it clear.
When I tried to ask who trained the hero, I meant the situation when Dealer has taken out a collar the hero was lured. Dealer said oh it seems that the hero was already well trained. I was curious about who did that kind of "training" to the hero, rather than who taught him to fight.
As for the reason the dad sent his weak ass son first before his OP daughter, we may infer from the dialogue. The hero thought that Alice was not strong enough (no better than him) and asked her to go home. Perhaps it WAS true before his departure. Something may have happened since then (and that's why their daddy changed his mind).
The reason I thought that Alice may have already turned into a witch is based on some information which looks like this is the situation:
1. Hero surprised by the power of Alice. (perhaps he was stronger than her)
2. Hero was not happy about female fighting witches. (perhaps there is a way to turn human into witch)
3. Hero could not believe that their dad would agree with Alice to come. (They may be from a witch-hunting clan. Maybe even if Alice becomes more powerful, their dad will not agree with her to come. However if she becomes a witch and takes control of their dad using witch techniques, this may become possible.)
4. Dealer calls Alice with the word "human" (brat for the hero), and Alice did not show any ability of using magic, so perhaps she is really human. The worst situation is that she has already become a colleague of Dealer, and they were just pretending.
