I would advise that you build up balista. Even though we don't know when dodging meta will end she will still be useful at lower level arena. You don't have to go all the way to 46, she have 2k fixed damage every 3 att.

And level 30 yeonhee is quite strong already.

both yeonhee and balista is needed in current arena..

just that balista wont last longer till next hero was introduce..

u can work on both heroes at the moment..