Hello Konoi!!
Thank you for your comment, it was very kind. What I can tell you is that Ariel falls under the 'evil' route. Each alignment has three characters to filter with and Ariel is aligned with the demons. Still, there are several things to keep in mind, being in the demons' point of view is not necessarily being a villain, the morality bar still comes into play and the demons' arc is designed to have its own antagonists and not so much hurting others. What the MC does most of the time in his lineups is deal with the problems of their territories and not so much participate in actions. It is also the most violent lineup and that must be taken into account.
Another thing to keep in mind is that the story endings will depend to some extent on being consistent with the actions you have taken. That is, if you have chosen the demons and your decisions have tried to be 'good', you will end up having a very high morality bar, it will generate distrust in you and it will have negative consequences, given that you are a main piece in the plot.
This explanation may not have resolved your doubts too much, but we encourage you to continue with the demon route, we promise that the MC is not a particularly evil character. On the contrary. The MC is the only one who manages to bring some order to the chaos.