Fire Emblem Fates: Heart Seal Class Swap Hack

So this is a hack of Fates that swaps every playable unit into their Heart Seal class line, even when encountered as enemies. Their original base class is available as a heart seal class. Children are swapped to the class line that their fixed parent passes to them in regular Fates. Exceptions to this are Corrin and Kana. If a unit is magically-focused and becomes a physically-focused class, their Mag and Str bases, growths, and personal pairup bonuses are swapped, and the same for physically-focused units becoming magically-focused classes. Generic enemies aren’t changed and generic/capturable promoted bosses that don’t have a heart seal class line simply swap to the other promoted class. I have also incorporated DeathChaos’s Revelation Unit Buff Patch for Revelation.

UPDATE 5/2/2020: Capturable enemy bosses are now in other class lines, they are able to access their original class line through the Heart Seal. Candace can reclass now.

Download Link is here: Heart Seal Hack Download

Additional Notes
  • Enemy only classes are not changed, Garon is unchanged in all appearances.
  • Promoted classes can now reach A Rank in their “secondary” weapon type(s).
  • S Rank Weapons are now A Rank so the enemies armed with them can actually use them.
  • Occasionally enemies have some of their skills switched to match their new class line.
  • Fujin Yumi is a 1-2 range Naginata, might reduced to 11.
  • Brynhildr is a magical dagger.
  • Missiletainn is a physical 1 range sword, hit increased to 80 and crit increased to 15.
  • Siegfried and Raijinto are an axe and naginata respectively. No weapon stat changes.
  • Various promoted enemy Nohrians in BR that are playable in CQ have received a buff. For example, Beruka has her 20/9 Berserker averages instead of the really pathetic stats she has normally.
  • Chapter 5 Dark Mages got a nerf because it was stupidly difficult on Lunatic to clear, even when sacking everyone.
  • Rev Ch10 and everything after Ch12, except Ch19, have increased deployment slots.
  • Spiced up Rev Ch15 since it was so boring.


  • In some cutscenes some characters are the wrong class, this doesn’t affect gameplay so I won’t be bothering to fix this.
  • Puissance still compares Strength since I’m bad, so it’s basically useless on Effie.
  • Some enemy bosses that become mounted (Iago, Zola) have their map sprites bugged and don’t have their heads properly displayed. They are fine in battle.

Installation Instructions:

There are two ways to install this hack: via Luma in-game patching or by rebuilding your rom. Both can be used with Luma, while using Citra requires the latter.


Luma In-Game Patching:

This is the recommended method if you are using Luma, however some users have reported lag issues when using in-game patching. This is an unavoidable consequence of how in-game patching works, and the only solution is to rebuild the rom and play the modified rom instead (see Rebuilding the Rom).

  1. Boot up your 3DS Luma’s config menu by holding the SELECT button.

  2. Turn on “Enable Game Patching”

  3. On your 3DS SD card go to “Lumas” folder.

  4. Create a folder called “titles” if there isn’t one

  5. Create a folder with the title of your specific game, if it does not exist already.

Fates SE JPN: 000400000012DE00

Fates SE USA: 0004000000179800

Birthright USA: 0004000000179400

Conquest USA: 0004000000179600

Fates SE EUR: 000400000017A800

Birthright EUR: 0004000000179500

Conquest EUR: 0004000000179700

  1. Copy the “RomFS” folder you downloaded for the Heart Seal hack into the title folder

Rebuilding the Rom:

This is a three step process. You will need to unpack the rom, replace the base files with the modified files this hack uses, and then repack the rom.

  1. Download .Net 3ds Toolkit, available at

  2. use .Net 3ds Toolkit to unpack your Fates rom. Run ToolkitForm.exe and use the “Extract” tab

  3. Once your rom is unpacked you should have a bunch of files and three folders with more files. One of those folders should be titled “RomFS”. Copy the contents of the “romfs” folder you downloaded for the Heart Seal hack and paste them into the unpacked RomFS folder. Agree to merge folders and replace files when prompted

  4. Use .Net 3ds Toolkit again to repack the rom. Run ToolkitForm.exe and use the “Build” tab

Also please let me know of any mistakes you run into.


Finally. Myrmidon Odin can wreck immediately now.