She's really good at C0. I'm playing her in the abyss with different 4-star weapons, and the results have been amazing. I'd suggest you use her as a support in your team with a hypercarry like Raiden Shogun or as an on-field character with supporting characters like Fischl, Kuki Shinobu, and Xingqiu. If you want better damage output, I urge you to use her elemental skill wisely to mark the enemies. Her elemental skill is really good against a group of enemies.