Here's a slopfest of a write up on what combos Venom can do out of K ball oki mixing up between empty jump 2K and low airdash jK jS/jS jHS/cross up back airdash jS if done from a close dash jump. His stand confirms are universal for the entire cast, barring the two big guys. His crouch confirms are a little more finnicky for a lot of the cast. Let me know if there are any mistakes.
Note that this is not a be all end all list of what Venom can do with K ball oki, just a starting point to get an idea of what he's capable of. Also keep in mind that my execution is not exactly top notch, so some combos may be possible that I simply couldn't figure out or execute.
Low option(Universal):
Empty jump 2K clS (3) 8 66 jS jHS jD 6HS xx oki
Basic high option(Slightly more damage on characters not listed in combo 2):
Low airdash jK jS/jS jHS clS (1) xx K QV, 6P BH 6HS xx oki
Basic high option 2 (Millia, May, Chipp, Elphelt, Ramlethal*, Venom, Ky):
Low airdash jK jS/jS jHS clS (1) xx P/S** QV, 5P BH 6HS xx oki
EDIT: Turns out the above combo is actually universal if you use P QV. This should be your go to crouch confirm if you're not sure what to do.
*Weirdly inconsistent on Ram. Sometimes after P QV, 5P will hit the ball but whiff on her hurtbox not letting you chain. It is possible to replace that ending series with S QV 5P BH 6P 6HS xx oki. I can't say for sure why this is more consistent, but my guess would be that either S QV knocks back less, it has some kind of miniscule vacuum effect after the hit, or it has less recovery on hit than P QV. Or maybe my execution is ass, both are equally hard, and it's all in my head. Who knows?
EDIT 2: With some practice, P QV 5P (BH) 6HS works when 5P whiffs and the ball continues the juggle. You just need to link 6HS instead of chain.
EDIT 3: I finally figured out why there were certain instances where it would seem like 5P after PQV wouldn't connect, most notably on small characters after a dash jump over airdash back jS. The clS after landing must be done IMMEDIATELY otherwise the pushback from the jS will make the followup fail. What I mean is that there seems to be a small window after landing where the opponent hasn't suffered full pushback and can therefore be hit by a 'closer' clS.
**Both work on Millia and Elphelt but P is significantly easier.
Advanced high option (Millia):
Low airdash jK jS/jS jHS clS (1) xx S QV, 5P 8 66 jS jHS jD 6HS xx oki
This may work on others, but the only one I could do it on was Millia. Further testing by someone with better execution is required.
Advanced Potemkin and Bedman option:
Empty jump 2K / Low airdash jK jS/jS jHS clS (3) 8 66 jS jHS jD dash jump (669) jK jS jHS jD 6HS xx oki
The only characters clS hits 3 times on crouching. For this combo, the second air chain has a heavy stagger to get the final jD to come out as low to the ground as possible. Input too fast and Potemkin/Bedman will recover before 6HS can connect.
General execution tips:
When doing one of his combos that requires a jump cancel into immediate airdash(8 66), input 8 on the move you want to jump cancel, and react to Venom leaving the ground to do the airdash. This gives you the timing for 8 66 which can only be described as an awkward delay.
If you're on a stick, try to get into the habbit of double tapping after QV. This new move's recovery is kind of deceptive, and Venom's combos almost always require the next button to be input only a few frames afterward. Double tapping ensures minimal room for error.