Jueyun chilli is used to ascend xiangling, and she's available for free after you complete Floor 3 of Spiral Abyss. This question will come to anyone's mind, and I would like to know the answer to it.  I'd say she's pretty good at providing AOE Pyro damage with her Pyronado, and Gouba can be put down to generate a few energy particles. Moreover, her application in vaporising and melt team compositions are pretty good, and she can proc those reactions very efficiently. I would advise you to invest appropriately in from early game, and she will even help you clear the most challenging spiral abyss content too!