The most efficient way to deal damage in any of these runs is by knocking the enemy into a corner and chaining together short and powerful combos. Most "juggles" as I will refer to them, go like this: launcher-> 2 attacks -> delay until back on the ground (combo will drop) -> hit of your choice -> launcher -> repeat. For example, I like to do Robo Fortune like this: c.HP-> j.MP -> j.HK -> delay -> c.MP -> c.HP -> repeat. The timing of your hits is important and will differ depending on the size and hitbox of the character you are fighting. When you delay, the enemy will do a random attack, call an assist, or switch out entirely. The idea is to keep them as low to the ground as possible to minimize the window they have to get a move in. Switching out will happen regardless but gives you the opportunity for a Happy Birthday. It is also pretty rare.

RNG and the character you're up against while doing this have a huge influence. Against an actual player, this would be impossible because they would just block, but the Sleepwalk AI will just use a random move, if that move comes out faster than what you start your juggle with, you will get hit, and you'll have trouble keeping a good rhythm. Valentine is generally a very hard character to juggle. She will often just instant air dash over you and out of the corner. One of the worst things that can happen when trying to juggle is losing the corner advantage. Some characters such as Big Band, Eliza, and Double, can be juggled midscreen consistently and into a corner. However, the timing is more precise and the chains may have to be slightly different depending on who you're playing. And some characters, like Big Band and Cerebella, can midscreen juggle almost anyone. Cerebella revolves around juggling anywhere on the screen.

Knocking characters across the screen as soon as the match starts is the best way to make use of juggling most of the time. Pretty much any hard knockdown move with enough range to hit off the start will do depending on the behavior of your enemy (I'll get to that shortly). Some characters, like Big Band, have many options, A-Train, Brass Knuckles, c.HP, Beat extend into A-train, etc. However, the effectiveness of these right off the bat depends on the character you're up against and what they do. For example, Parasoul will often immediately lead off with a Napalm Shot or two in Arcade Mode. So the best option would be H-Brass Knuckles to tank through the hit and knock her back. However this is riskier against other characters. If a character jumps at the start the move will almost always miss. Furthermore, Cerebella will almost always lead with an armored move which will just tank the hit. It is good to figure out how many and how effective your characters hard knockdown options are beforehand. Anything multi hit (ie. Squigly's and Robo Fortune's lvl 1, Beat Extend) will be the go to in most situations.

Generally speaking, the bigger the character the easier they are to juggle. Double is the easiest because of her size and weight combined with her lack of any threatening moves, and Valentine and Squigly are up there for the hardest. Squigly is incredibly small and notorious for funky hitboxes, and Valentine as mentioned earlier is incredibly slippery. There are a few exceptions to the size correlation however. Beowulf while quite large, can be a bit wonky when juggled by certain characters, multi hit moves can often lead to you sliding across him and ending up behind him facing away from the corner. Ms Fortune while appearing to be quite limber, is easier to juggle than most characters big or small. her lack of dangerous moves and normal hitboxes make juggling rather simple.

This is all based on what I've figured out from my own runs plus taking a look at a few others. I hope someone finds this useful one day :)

And don't be afraid to experiment! There could always be a better way