I've recently come across two fanmade comics which depict the player character of Pokémon Ruby/Sapphire/Emerald trading one of their Pokémon to FireRed/LeafGreen, then transferring it to Diamond/Pearl/Platinum, which is then traded to HeartGold/SoulSilver, Black/White, Black2/White2, X/Y, and finally back to OmegaRuby/AlphaSapphire.
When this happens, we get a heartwarming scene with the Pokémon being reunited with his original trainer.
Watching those comics made me wonder if anything special would happen if a Pokémon were transferred all the way from RSE to ORAS. Since I never owned any 3rd-gen game, I can't verify this for myself.
Here are the two comics: