Using Jack-O's Servants in neutral [Guilty Gear -Strive-]
To do any of them you hold P after Summon Servant, then jump, use j.D to release it and hit it with an aerial as fast as possible.
j.P: sends at a nice angle below and in front her, but I would use it just to setup the j.S (as shown in video), since j.K does a better job that it. Better use to air dash and setup a j.S
j.H: sends it REALLY far and REALLY fast, would use it from fullscreen away and set them behind the opponent if their back isn't stuck to the wall. Risky using up close since it would go over the opponent and would leave you vulnerable, but really optimal to use fullscreen away. Best use as a fast fullscreen projectile.
j.S: in my opinion it's the best one. It's active to hit the opponent throughout the whole ground bounce, so it's a lot of time to hit them and it cover a good portion of the bottom half of the screen, that can be very difficult for the opponent to go around it, giving you a lot of screen control and more time to setup ANOTHER servant. Not only that, you can cancel j.S with an air dash after hitting the servant, giving you movement while still having the the minion behind you. Best use in neutral from the midrange or full screen.
j.K: Better version of j.P in my opinion. Sends at a good angle in front and below her, but it's better than j.P because you can cancel it with an air dash, while j.P had to wait for their recovery of the move to finish. It's a good way of getting in from a mid range distance if you fall with a j.S, since it hits very far below her. Best use at midrange as an approach tool.