Base weapon/magic damage * (1 + 0.05*(Stat + Weapon talent)) * (1+0.05*warfarelevel/elemental level) * (1+critdamage if crit +highgroundbonus if highground)
That's the formula I use to always get the damage and tested in both GM mode and story mode. Apply resistance to final damage.
This doesn't seem to explain why (at least in my test with 57 int and 15 Aero), removing 2 Int was approximately the same damage reduction as removing 1 Aero.
