Beorning debuffs broken?

[Frisco]

They apply their stated value, they just happen to be mastery debuffs rather than a multiplicative multiplier. Bosses generally have rather high mastery so it's not that big a reduction overall.

Only burgs/LM's/Champ (the -30% taunt) debuffs are multiplicative, every other damage debuff is a mastery reduction.

I don't know if that can be considered "stated value". Slam says -10% damage, not -10% mastery rating. If that's the case,it should state that it's a -mastery debuff like a LM's Deep Freeze debuff.

A 10% mastery debuff comes out to be exactly 2.5% damage debuff every time. That would mean that every mob has 400% Physical/Tactical attack damage for some reason.

And while Slam has different wording, Piercing Roar at least states -Tactical damage exactly the same as Addle/Frost Lore does. The same wording means two completely different things?

Something needs to be fixed, either the tooltips or the debuffs.