Damage tooltips seem to be incorrect on the PS4 version of Divinity, particularly regarding buffs such as Oath of Desecration or Melee Power Stance. Just did a bunch of testing, and I was getting damage values in the combat log (including absorbtion/armor/resistances/etc) that were well below the minimum damage values in the tooltip, and I never hit anything near the max damage values advertised. I even tried testing with all armor removed, same thing. Oath of Desecration, Melee Power Stance, etc were indeed multiplying damage on the tooltip, yet when I tried actually hitting things there seemed to be no difference in damage between using buffs and not using buffs, which seems like a pretty significant bug.
I've tested on enemies as well as on other party members with all armor removed on Tactician mode, and the issue was persistent. For example, I would try Melee Power Stance / Oath of Desecration Crippling Blow, the tooltip would advertise around 350-650 damage, and I'd deal 200... on a character without any armor.
