It's....hm. I haven't had to explain it exactly. It's like the basis of life? Crops wilt and droughts come when the world is declining and mana becomes scarce, like in my home of Sylvarant. That's why it's so important for me to have left Iselia for my Journey. It's also the source of magic, how Genis has his ice or fire magic for example, and the Professor can heal and use sort of like light magic I guess, but only elves or half-elves can use magic.

[Yeah, she still has no idea they aren't full elves. Yet. But this is at least hopefully a basic enough explanation for him to understand? He at least comes from a world where powers were common so this probably didn't seem too weird to him? That he's so excited about her being an Angel and such.]

I'm not sure. It might be worth a try though? We won't know until we give it a go, right?