The trick is in mixing things up, afterc2c you can 5D(1) dash or DS, you can 3C, 2D, 6C, 6D, 6B, HF.
2C is one of ragnas best moves, u just need to use it right.
Oh and Moy, theres no way ragna is bad match up for plat. She does same of dven more damage, her normals are hakumen grade and her pressure is pure craziness, ragna is half the character she is.