This demo showcases an Arbitrary Code Execution exploit used in Pokémon Diamond, capable of hacking any GBA game's save data. In this case, putting a Manaphy (or any other Pokémon) in gen 3. The hardest part was getting ACE to persist through soft resetting, more info soon.

Combined with the Mystery Gift ACE exploit, this means Pokémon Diamond/Pearl's ACE can now give ACE to: Platinum Heartgold / Soulsilver Ruby/Saphire Firered/Leafgreen Emerald And technically, any GBA game as long as an ACE exploit can be triggered through editing it's save.

That's awesome

Incredibly cool. Are you planning/Is there a write up?

Only started the research less than 48 hours ago, so still developing stuff. But a write up will come!

okay this is crazy

This looks cool! Question, if you edit Emerald’s save to have a Manaphy on it (or any gen 4 mon for that matter) like you’ve done here, then load the Emerald save, how would the game react? Would it load as a glitch Pokémon, or just crash the game altogether?

@ZephyrBreezy In this case it'd be a glitch pokémon with the id of manaphy, of course you could do some extra stuff to trigger ACE in gen 3 and actually load a manaphy sprite there.

How much data can you actually send to Gen 3 through this?

You can edit the entire save file.

Kooky