That's always been the key factor for me for each successive task. Each task needs to be just that little bit further down the slope of corruption, but not too far, so Sophia thinks, why the heck not, it is not much worse than the last task, without stopping to realise how far she has come in total progression.
I think someone has said that, at one point, Sophia thought that Dylan could handle Aiden one-on-one, but does nt think he could handle the whole of Aiden's gang. Therefore with one day of martial arts training, and having seen Dylan handle the drunk hobos in the park, to me nothing has changed yet. At this point I feel Sophia is still doing Aiden's tasks in her mind to protect Dylan.
I did wonder personally why Aiden told Sophia that he was Ares. I initially thought he would be better off not telling Sophia, as she had started to enjoy herself at the art class, and without that revelation, I was thinking Sophia would be willing to go further in the next similar situation.
But by telling her then, Sophia was initially fuming, but she has the evening ahead to distract her from resenting Aiden. Thus by giving her that time to assimilate, in Sophia's mind she is still trying to protect Dylan. So she would have to accept Aiden's 4th task at school in the literature class. The 4th task can't be similar level to the 3rd task as it is in class. But hopefully it is not too far a step back - surely it would have to push things further than 1st and 2nd tasks.....