Can RNG Correlations determine legality of Pokemon from gens 4 - 6?

[Route217]

I have been on a gameplay binge going from gen 4 (diamond) through every retail game (thank god I still have all my cartridges) up until gen 6 (ORAS). RNGing has let me live my childhood dreams of playing through my favorite games with cool shiny pokemon. RNG had given my attachment to pokemon a new life, and I got way more use and playtime out of my games. Because they were all generated naturally, I had no doubt question of their "legality". 

When I got to 3ds I started using PKSM, and when I realized I could, I edited my Heatran and Cresselia's IV's from Black 2 so I could use them in the Gen 6 Battle Maison.
After reading albert's post I just had a quick question about rng correlations. I used PKSM's legality check server on them after editing and it still came back legal. I read somewhere that this server was heavily based on pkhex.core, which I assume has a strong legal checker. I wonder if my heatran and cresselia are legal and if not how I can change it back to the way it was so they are legal and entirely possible to be generated by the game? For integrity's sake

I guess my followup question would be which games have predictable RNG that can determine legalness when checking the IVs (or maybe like met date and seeds, other data etc.) and which games any outcome is possible, even a perfect IV shiny cresselia from black 2?

[Kaphotics]

Gen5 was interesting in that the PIDRNG was separate from the IVRNG, aside from mystery gift encounters. So there's no detectable correlation for the Gen5 Pokemon you mentioned.

It'll still draw suspicion if they're perfect shinies, as the games were difficult to search for seeds that yield those results.

[Route217]

Thanks, make sense. Can the same be said for gen 6?

[bluefoxlad]

On 8/22/2023 at 8:58 PM, Kaphotics said:

Gen5 was interesting in that the PIDRNG was separate from the IVRNG, aside from mystery gift encounters. So there's no detectable correlation for the Gen5 Pokemon you mentioned.

It'll still draw suspicion if they're perfect shinies, as the games were difficult to search for seeds that yield those results.

I actually had a question on that subject. Given the current correlations, is there any way -any program that could be used, maybe- to check the legality of a genned Gen8/9 mon beyond the regular check that PkHeX does. I mean some way to actually check if the PID, IV, Height, Weight, etc. correlations of the mon are perfectly legal?