http://db.gamefaqs.com/console/ps2/file ... istory.txt
Anyway, they state that Promathia was the cause of weaknesses in the five races Altana created:
The elvaan, obviously, have arrogance as their weakness (being rudely insulted by Halver during the last Rank 2 mission despite being there to save his butt drives that point home, and the guards aren't friendly either).
The humes have apathy, which is believable considering their treatment of the galka.
The tarutaru have cowardice (witnessing a tarutaru "guarding" the Horutoto Ruins nearly wet himself when confronted by cardians in an early Windurst mission confirms that prejudice

The galka are plagued with rage as their weakness (Bastok is full of disgruntled galka).
But according to the FAQ, the mithra have "envy" as their weakness.
Envy?
I'm trying to think of situations where mithra have proven envious... but I really can't come up with anything.
