All right before you all jump on the “Diana is such a bitch!” train let me stop you. She is not bullying Akko. Just like in episode 5, she is merely pointing out her faults, which are things Akko would do well to recognize and fix, for her sake and for the sake of those around her. When Diana yells at Akko, Akko listens and takes what she says seriously. It might be the only way to make her listen to Diana, since Akko is so tunnel-visioned and sees her as her rival. And most importantly, the things Diana says only serve to motivate Akko.
A main reason these two are always clashing is because Diana comes from a family that is steeped in tradition and the traditional usages and practices of magic, while Akko has said multiple times she has no interest in “becoming like those old hags”. She wants a new, more modern magic.
As they are now, they cannot accept the other’s ideals/views of magic. I would really love to see them come together somehow to appreciate the other’s viewpoint, whether it would involve Chariot (and Diana’s secret love of her) or not.
But there is SO MUCH potential for them to overcome their differences and work together and to join the two types of magic together, and I really hope we get to see it.