3DS-rom-tools VS open_agb_firm

This is the one I have been using (https://github.com/ihaveamac/3DS-rom-tools/wiki/SeedDB-list). Make sure to put it in the same folder as the decryptor.

I use the custom-install program to install games, where you need to provide your own seeddb, so I downloaded one from custom-install's maker - https://github.com/ihaveamac/3DS-rom-tools/wiki/SeedDB-list

For open-source tools, Project CTR includes ctrtool to extract many 3DS formats including CIA, and makerom to build an NCCH, CIA, or CCI file. It's a bit old so I'm not positive it'll work exactly, but there's a guide on extracting a CIA using ctrtool and 3dstool, then rebuilding it using makerom and 3dstool.

Basically, you would need a tool to unpack an FE15 3ds file, load the files into Paragon, edit the skill on everyone you want and then repack the edited files with the rest of the unedited files from the game, and play. If you're wondering how to unpack and repack 3ds files you may find this resource on github to be useful.

Link: https://github.com/profi200/open_agb_firm/releases/tag/alpha_2023-10-6

Don't forget about emulators! Especially if you have a "new" system - you can even play some (mostly 2D) PS1 games, and some N64 games on it, and everything older. On an "old" system you are more limited though - SNES games that use a SuperFX chip (such as SM RPG, Yoshi's Island, Star Fox, and some other ones) will run slow, but Genesis and 8-bit systems will run no problems. And you can run GBA games - on "new" you can even use the system's gyroscope for games like WarioWare Twisted or Yoshi Topsy-Turvy through mGBA, and on any system you can use injects or open_agb_firm - they both run games natively using the ARM7 CPU - the same one GBA uses, carried over into the DS, and it's still included in the 3DS.

Github

Use open_agb_firm. It's a firm, so it's activated in the same way as GodMode9, hold START while turning on the 3DS. You should be able to download it via Universal Updater. open_agb_firm uses the 3DS hardware to give you the same experience as playing on a real GBA.

That depends on how you are running the game on your 3DS. The best way is with open_agb_firm, in which case you will probably need to convert it with https://exelotl.github.io/gba-eeprom-save-fix/ (as linked from https://github.com/profi200/open_agb_firm ).

If you're playing a GBA game, open_agb_firm or a VC inject are your best bets.

You could use open_agb_firm to play your GBA games instead.

Because unfortunately mGBA is a little bit laggy on the 3DS. It’s terrific for game boy and game boy color games, but I digress. You could use something like open agb firm which runs games using the 3DS’ built in gba hardware natively without any lag or slowdowns.