jD is a wild card, it depends; Using C as your body and ascii to badly demonstrate opponent's height;
C ' : You can hit 6A or d2B
C- : You might be able to hit 6A, and if yes, can hit d2B
C_ : You can't hit 6A, and if they're really low you probably won't even get 2A, much less 2B or d2B
jD has hit stun til they hit the ground +x number, so the higher they are compared to you, the better. That's why 5B 2B 6C jD connects to 6A perfectly every time, the 6C puts them optimally high.
On 2C, you can always get d2B, and that is the 5+ I was referencing.
And blackbeating = combo dropped, they can tech, but it keeps going anyway because they missed tech