What do you need: NDS Fat / NDS Lite with Slot-2 you game to inject that save (i tried with Yu-Gi-Oh! Worldwide Edition: Stairway to the Destined Duel) (USA Version) You save you want to inject (.sav format) NDS FlashCart can run Homebrew (i tried with R4i Smart Update 2016 and worked perfect) GBA Backup Tool Visual Boy Advance <- THIS IS ONLY FOR CONVERT .SPS TO SAVES I AM NOT RESPONSIBLE IF YOU LOSE YOU SAVE DATA OF YOUR GAME, USE AT YOUR OWN RISK Step 1) Download GBA Backup Tool, and put it in your NDS Flashcart (where you want) Step 2) Make sure your save is in sd:/GBA_Backup/(filename).sav Step 3) Insert you GBA Game, start GBA Backup Tool (Backup you GBA Save if something worked wrong, save doesnt worked, etc) Step 4) Change command with R (Save Restore), and with the D-Pad select the correct save of the game (MAKE SURE IS THE SAME REGION TOO) and press A (Restore Data in Card from SAV file) Step 5) Test you game FAQ: I Downloaded a .sps file save, how i can convert it to .sav file? Download VBA, click "File" -> Load your Game/ROM -> Import -> Gameshark Snapshot -> (select the .sps file) -> OK -> you should get the .sav file in the same directory of the ROM WHERE I CAN FIND A .SAV SAVE FILE?!!?!?!?11?!?!?!1?!?2!? google it, like GameFAQs have some GBA saves .-. SO I CAN MODIFY MY POKAHMON SAVE AND MODIFY AS I LIKE?!?!1'1!?!?!!?? Yeeeeep, just extract (backup) your save, take it, and execute Pokahmemes save editor, like FireRed, LeafWeed, etc. The best part is you can put pokahmons shinys, inject pokahmens, items, unused items, etc etc. Note: Some games are identical, like Yu-Gi-Oh! Worldwide Edition: Stairway to the Destined Duel (USA) and Yu-Gi-Oh! Duel International Monsters - Worldwide Edition: Stairway to the Destined Duel (JP) so, can run the same save, i tried to inject a USA Save with Yu-Gi-Oh! JP and worked!! note 2: if you game is bootleg, maybe this doesn't work since they have bad load rom, bad checksum, etc. Better do it with original games, speciall with Pokémon games.