Sorry, I'm lousy at explaning things. The hitboxes are hard to explain unless I make a video. I suggest you try it yourself. Grouping them into different difficulty is much easier than trying to explain individual hitboxes effect on Arc. It is all about hitboxes and height of your combo. If you don't understand this, you will definately miss your wallslam and relaunch. Sure you don't miss on Akiha but what about V.Akiha?
Judging from the videos I saw in Youtube, some of you did not input 2C in your combos. 2C is important due to its huge untechable time. Almost all of her extended variant or advance (or SII style combos\CMV) requires the usage of 2C. There are alternative for her extended combos, 2C is way easier due to its non strict nature.
Some basic idea why 2c is important as follows:-
5B > 2B > 2C > 5C > 5A > 5B > 5C > 5A > 5B > 2B > 2C > delay 4B > j.B > j.C > J.A > j.B > j.C > Air Throw
5B > 2B > 2C > delay 4B (2 Hits) > j.C or j.B > Land > 5B > 2B > 2C > Half Charge 5C!! > Special Air Dash > j.A > j.B > j.C > j.A > j.B > j.C > Air Throw
Those CMV videos which send you flying left to right.... some of it apparently works on Akiha and Arc(free 5C reversals). I'm still testing this. They don't yield more than 4300 damage even you manage hit up to 50 hits. They need two 623C to maintain the juggle but worth it you want to burn time. Screw proration, I want cool looking combos ><".