I used trice's google doc dps calculator to math out the best possible dps combinations. This build assumes hitting weak point 50% of the time.
screen shot here of maths here:
https://ibb.co/qmqrchJ
BIS would be to chance element to whatever boss is weak against. If you don't like real-life fighter you can switch for element conductor, for similar dps. I like real life fighter because it allows me to switch element without having to use crystals.