it's time I tried her out?

I rarely use Mystics in content though. My current roster reflects that as it has very few r5 6* Mystics: White Tiger, Destroyer, Kindred, and Rintrah, and 2 high rank 7*'s: Chavez and White Tiger.
That's it.
But let's see how it goes. I hope her AI will spam heavies when I put her on defense, like it does so often when trying to fight against her lol.
And in case anyone asks, she's only r3 because I had gotten a Mystic 2-3 gem from Necro, and she was the ONLY 7* Mystic I had at the time. So I had to r3 her to get Valiant.
If you are a Chavez user, how has your experience been with her?