Well, I was going to say that was ridiculous, but it doesn't even reach inane.
Thanks to those who gratz'ed me though. =P Anyway.
My thoughts about that:
There are different kind of "dmg-buffs". So it only scales for "holy-dmg" ... not "holy-spell-dmg".Thats the reason u dont benefit from spell-dmg flask. U need to find buff that increases "holy-dmg". At least thats the way i remember the correct mechanics for wand dmg. I think thats the same here. But i could be wrong.
That's an idea. A problem is that the spell appears to be from the shadow school so it seems counterintuitive that straight holy dmg is what boosts it for a paladin; given the numbers from the Loatheb fight imply the spell scaling with attack power, I suspect he saw that number while having blessing of might up.
Still, if we go for the holy dmg idea, the only buff I know off that I can use as a warrior is the pally
sanctity aura (which if it works it'd give an increase of at leeast 20 damage or so). I don't expect it to work but I'll check it.
If the Procc is Shadow School then it has to be "shadow-dmg" buff. U could try out stacking Debuff from Shadowpriest on your target.
Loatheb is Undead so the Paladin does more Dmg because of its dmg-boost against Undead-Target.