Ragna vs Nine

Vs Nine

Neutral
•Neutral game is what's going to make or break you in this matchup. You have a lot of range to try and work your way in but one wrong move and she just dashed away/punished you. Her buttons also have great range but are just slow enough on recovery that you can get a whiff punish, or at the very least force her to block and let you get in.
•Nine is going to try and bait you into pushing higher recovery buttons during neutral by using her dashes. Use low commitment options like 5A for anti air, 5B for poking, and j.A for air to air situations.
•If you have 50 meter you might want to try and go for a j.214D or j.214B to close the gap during neutral. You can use them after exhausting all of your movement options or for something more explosive like a TK.j.214B to cover a huge amount of the screen at once. Try not to rely on these too much though as they're not a substitute for proper neutral game. You want to use them just sparingly enough to put the fear in Nine.
•Her options to control the screen from the ground or air are both very solid so there really isn't a preferred method of trying to get in. Keep her on her toes by trying to attack from the ground and air equally while also applying barrier braking/neutral jumps to try and catch her overcommitting.

Offense
•Once you get in range she's going to try and push you out with barrier until she can use one of her defensive options. Try sticking to mostly A and B normals for your pressure and get ready to punish/chase down her backdash attempts. Make sure you use 236D sparingly, all of her 4 normals can be used to eat the deadspike.
•On knockdowns you want to meaty her so she can't get away with backdashes on wakeup. This can get more annoying midscreen, especially if she has meter for her faster reversal. If she doesn't though just make sure you watch out for and punish her meterless DP with an instant block.


Defense
•Pay attention to what spell she is currently building towards. Kunzite is a fast overhead but it is telegraphed thanks to spell combinations. Keep her in check by using 632146D to go through Kunzite, preferably while she is on the ground for a better punish.
•Barrier helps to escape from pressure midscreen but Nine's range is so large I wouldn't really use it until you're at least a 5Bs length away. With any luck you might be able to get her to whiff a 3C with proper barrier timing.
•Most of the time Nine is going to be out of range to try and go for a DP/GCOD. Save your bursts for when you need to deal some damage/get some life back or for when you're stuck in the corner.
•Be mindful of when she freezes you mid combo for a potential reset. Just block low and get ready to react to a Kunzite.

Summary
•It's a tough one, probably around bottom 3 matchups for Ragna. She has further range than you and doesn't have to commit nearly as hard during neutral. Her offensive pressure doesn't generally allow for system mechanics to work on her thanks to said range. And to top it all off her defensive mechanics make sure you play with no holes in your offense. The neutral game is stilted, but if you can get her to the corner you can work your offensive game much easier. If I were to prioritize any matchup a player should learn first in BBCF it would definitely be Nine.