Hi, I'm new and I'd like to give my opinion on this. Choosing a favorite character is difficult because I've liked them all or found them to be okay, each of them seems interesting or charismatic in their own way.
If I had to choose one, it would be one of the main trio (Asterion, Luke or Kota), mainly because you spend more time with them and they have a more active participation in the important events of the game. Oscar and Pedro are also strong candidates, at first I didn't expect much from them but I ended up being captivated by the story of both. I can't decide on one in particular.
The one I like the least would be Themba, but not because I consider him a bad character or anything like that. But because in the route I've played I chose Khenbish and Wolf and I haven't been able to interact with him. I thought he would join later as has happened with the others but I finished the chapter 19 and he hasn't shown up anywhere. XD
I'll have to play the game again to draw conclusions hehe