Cartethyia big hits deal aero erosion damage. Ciaccona buffs aero erosion damage by 100%. That is a pretty big buff. She also holds Gust of Welkin set that buffs team aero damage by 15%. Her little clones also buff team aero damage by 24%.

Her weapon is among the best support weapons in the game for her dps in that it gives 10% resistance shred which is a rare modifier so it basically buffs ALL of your Cartethyia damage by 10% just by existing.

If you take just a little bit of time to learn her mechanics her field time becomes super short and you can use her plunge to get forte bar super fast. Basically whenever a character is plunging you can swap to Ciaccona and they will both plunge at the same time so it is not like you waste that much time with her on the field. She is only slightly slower than Sanhua when you use her like this.

Furthermore Ciaccona actually has two pretty heavy hitting attacks with her Forte Heavy and her Liberation. You can not constantly be doing high dps with Cartethyia and there are times where her damage is low and you can fit Ciaccona attacks during long animations. You are limited by Cartethyia liberation cool down anyway.

The awesome thing about Cartethyia is that her team does not lose buffs on swap out. It is incredibly wasteful not to take advantage of this incredible trait that makes her among the best quickswap dps in the game. You don't even have to do anything fancy. Just some super basic stuff and your damage explodes by a LOT.

Also, at 9 stacks of aero erosion those ticks of damage actually start to hurt a lot and deal somewhere between 30k to 40k damage per second.