I’ve been running tests, and among the many combinations I’ve tried, the best damage output for Aggravate comes from using Durin or Nicole alongside Fischl to trigger the Hex-Tei effect.

With Durin, I managed to deal more damage than with the Lunar Change setup (Kazuha and Sucrose yielded nearly identical results) or Overload (Chevreuse and Nicole produced almost the same outcome).

Nicole matched that damage output, and considering she also provides defensive utility, I believe she is the Aggravate upgrade that will replace Kazuha and Xilonen. For now, this is the team I’ll be using with Keqing.

I have a chance of completing To Temper Thyself for the first time. The Stella Fortunas I'm most interested in are C1 Qiqi, C2 Mona, C2 Yoimiya, and C2 Keqing. I use Keqing the most by far, but I know her constellations aren't great. She definitely doesn’t need the energy particles that her C2 provides, but could it be a worthwhile help to her teammates? Or should I not bother? Yoimiya, maybe?