Is there an investment chart for a main DPS Rin team?

I’ve just pulled E0 Cerydra for my Rin team so I’ve currently got just E0 Rin, E0 Cerydra, E2 Sparkle and E0 DHPT.

I really love this team and obviously Rin so what is needed next to further invest in this team. I don’t have any signature lightcones so would that be next? (Rin is using The Herta’s sig LC, Cerydra is using Robin’s sig and Sparkle is using S5DDD)