I found two characters that I really like, but I’m really struggling with finding a good third to pair with them. Any advice?

Basically above. I really have grown to like Nova a lot. I also really like Amaterasu, it was the character I was initially drawn too because I just really like Okami. I think the two work well enough together, but I’m having a hard time figuring out a third character that slots in well with what the pair is trying to accomplish. I should probably note that I’m definitely a beginner, I’m still working on getting basic combos down, as well as learning general game knowledge and some tech as well, so I’m just a bit overwhelmed. If you all have any advice as to who I should try and learn for that character slot, it would be a great ease on me. Thanks in advance.