>>15434194Currently, we don't know how "tight" Nintendo's legality checker is online. The gen V one were a joke since it only checks for illegal movesets, stats and EVs.
Pokecheck.org went further by checking your PID frame, so some hacked Pokemon will still show up as legit in online GTS but "hacked" in Pokecheck
In gen 6 currently there is a lot hexes with unknown functionality, some of them might store info regarding the said pokemon parents' IV, etc so your "edited" pokemon might not pass the online Gen 6 GTS legality checker.