During the Beta phase, I've found conflicting sources that state what Piety does and of course what INT or MND does as a result.
http://www.ffxivguild.com/ffxiv-a-realm-reborn-stats-and-attributes/
"MP Pool"
http://ffxiv.gamerescape.com/wiki/Piety
"Reduces chances of your magic attacks being resisted."
So I'm wondering if this is because of a mix up of 1.0 and 2.0 mechanics or one site is just wrong. I didn't play mage much so far in XIV, but I did notice 1 Piety equals 1 MP. I wasn't able to test the other claims though. If anyone has a good understanding of this, please assist.