What is the breakdown on horntail's attacks?

Thanks Cyanne. I notice that defense up seems to dock off a consistent 20% damage or so, I don't think it modifies the monster's defense and cap at 1999, because theoretically that will reduce base range by 1k or so before skill modifiers but I've seen 50k hurricane crit going down to 40k everytime it buffs up. 75k stars also go down to like 61k or so. That thief boss in cwkpq I seem to be able to do 50k crit as well and he has 1999 defense.