Quick disclaimer here. I watched the first 3 matches, 2 in the middle starting at 39 minutes, and 3 at the end. I wanted a quick assesment of how you faired throughout the set but if there is a specific game you want me to view feel free to let me know! And I'm not gonna lie the set really is hindered by the massive delay here but I'll point out some things that I think would help out even still.

-Be more aware of your burst usage. Using it on the first round of a game should only happen in very rare situations. Stick to use it to close out rounds or turn the tide on defense.

-5D is a very situational anti air that I don't recommend going for very often. It's a big risk and the reward isn't exactly worth it without 25 meter. And that's only if you get the 5D(1) hit confirm.

-Make sure to use all of your meter first to finish a round instead of using OD if you can. OD transfers after all unlike meter. This applies to your combos as well, if you can close it out with 50 meter make sure you recognize that situation going into the initial confirm.

-Recognize Mu-12's 6B overhead ranges and attempt to fuzzy out or mess with her timing via instant block barrier.

-Sort of like the Nine matchup, you are going to want to play risk aversion as best you can here. I'd say almost even more so thanks to Mu's more explosive damage. Stick to non commital moves and slowly work your way in during the neutral phase. And keep in mind that you can use carnage scissors on reaction to punish her from fullscreen too.

-Delay 3C safejumps are hardly ever worth it when you are cutting off that much damage like you have been in the set. Especially when you could just OS her DP instead.

-Be more proactive on defense. Quick fuzzyjumps are the name of the game defense wise in blazblue, especially in the corner! It's a fairly difficult thing for a lot of characters to just punish you for doing.

-Choose between either j.A or j.C while in the air. j.B is hardly ever worth it really. j.A for checking airspace and faster startup, j.C for range and moving in offensively.

-Round starts should almost always consist of microdash 5B, jumping forward j.A/barrier, or waiting just a tick before commiting to any action and see what your opponent does first. You mostly had this down but I noticed a round start 6D and use of run up 6D in neutral and that got me a little more than worried lol.

-Point blank deadspikes are a /really/ bad idea lol. If you are that close just stick to 6D instead. Feels like you have an over reliance on deadspike in general really.

-Use j.214C more often to bait out Mu's 6A.