Heres the ranking of what your CS really depends on most in this game.
CS Boosting Items Ranking Guide
All the stuff below should give you 33k CS to 40k CS
- Legendary gear
If you roll right each gear will give you 3k CS at 5* upgrades. At average 2.5k.
Roll for hp and resistance stat if you want to tank the easiest way to get highest CS.
Roll all Atk stat and crit if you want to be dps.
- Weapon Ascension
Each star gives huge improvement believe or not. Altho you shouldnt buy weapons in store to just upgrade the stars rather explore and use the weapons you have highest stars on.
A 5* matrix set 2pc on each weapon will get the weapon to 5k to 6k CS. Try to get as many SSR matrix as possible preferably Crow and Samir. Then shiro matrix 4pc for your support weapon. The roll machines give you samir matrix in Mirroria city costing 500 ecoins for 10 pulls.
This is only possible to get from limited banner. Check banner list and get the team resonance you want.