Sure, that sounds like a cool concept a Witch of Heart could potentially play out through. Who knows what the “best combo” would be though, it’s a story so if you take the time to think out how the other personalities mingle with the character and set it up well, you can justify pretty much anything.

You don’t need to worry so much about what the mechanically “Best” classpect combo is–I’m not even sure an answer to that exists. Just use the system to tell the story that feels right to you! You can do it ^^