Help regarding team build and cycle

So I managed to get s5 Cartethyia almost s6 im just missing a few pulls but a lot of the guides I’ve been seeing only mention s0 her eidolons apparently make her less reliant on aero rover and I don’t have Ciaccona so who should I pair her with? For reference Sanhua is being used in another team so my options right now are aero rover aalto and jianxin Also what echo build should I run with them