In CoreQuests.xml you will find many modifiers such as these
<GameModifier InternalName="Reward2">
<ModType>Player</ModType>
<Attribute>UnlockSpell</Attribute>
<StrVal>ShadowWorld</StrVal>
</GameModifier>
Remove these from the quests, and add them to whatever tech (Only-SP/Techs_Amarian.xml) you feel it belongs to.
As always, when modifying Core (installation) files, you'll need to create a shortcut to FE, with the following target:
"C:\Program Files\Stardock Games\FallenEnchantress\FallenEnchantress.exe" -localdataonly
Also, be sure to back up any files before you alter them, as you will need to restore them before patching the main game. Read more here: https://forums.elementalgame.com/420611