Polynesian for the original source of mana as a loan word would be cool. I also find stuff like Aztec would work really well for an RPG.
If I had a wish though, it would probably be to make a scaled down world that samples most of the historical cultures of each continent. Then do something where quests need you to do a bit of syncretism to solve them.
I frequently use Kate as a backup as well. Do you configure it in anyway?