Custom Explosher - Sprinkler - Wavebreaker
Sprinkler helps movement of Explo, and Wavebreaker locates and chips opponents, which are both amazing for Explo.
Custom E-liter 4k - Burst Bomb - Ink Storm
Burst helps with close up fights when someone closes the distance, and Storm is just a nice supportive special for almost any backline.
Heavy Edit Splatling Nouveau - Squid Beakon - Crab Tank
Beakon is good on most splatlings, because they don't want to be using a sub too often because they would have to drop their charge. Crab Tank would help Heavy Edit with it's tougher longer ranged matchups.
Bamboozler 14 Mk II - Burst Bomb - Super Chumps
Burst has always synergized with Bamboo historically, for damage combos and paint notably. The same would apply for chumps, while also providing some cover.
.52 Gal Deco - Curling Bomb - Reefslider
While I don't have much to say on the synergy of Curling, it does allow you to sneak in for easy 2-shots. As for Reefslider... It would combo with the 70 damage radius I guess...?
Foil Flingza Roller - Suction Bomb - Splattercolor Screen
Suction is and always will be a solid sub for almost anything. Now I know screen on a roller night sound weird, but hear me out. Flingza can farm specials easily, and it can go in with it's own screen close enough to see through it. It can use that in clever ways to sneak up on people for a quick one-shot.
gonna continue this tomorrow because im sleepy