Originally Posted by
Itoshira
Let me try to break down some things.
First of all, Water aint the fastest of the elements, so a Hime like Diana is not a big issue to have in there.
At that point of her release you also got Cthulhu AW. She can give an additional 20 BG to party if her Orb Eater has success.
Now, the other thing is, Tiara Accessory Sets are in general mandatory anyways. That's a huge boost to the speedgame.
Still, you cant compare Water to the likes of Light or Fire where some Hime just have a speed where not many can keep up with at all.
Now, lets consider Diana's influence. On one hand, she has her 100% BG Skill. You can use it in different ways, either to make sure she can line up with all others, be a connecter for Bursts or use it as an additional 10BG gain. This highly depends on the situation you are in and is nothing to be set in stone.
The other part is, she gains 20 BG after Burst, this lets her stay on pace for the follow-up cycle, so she doesnt need someone like Saras to let her keep up. In addition, she has a DA passive, so that helps as well.
Here is now the big thing: She offers a Vigor-Party-Buff + dmg cap increase, which is not only a rare but also a strong buff in this game. Combine all this together and you have a solid Hime that is on a medium pace with some strong support.
Conclusion: It is still hard to tell if she is top-tier or not, but, she sure helps Water to have a solid pace and increases the overall damage.