Armor piercing conversion question

I understand the basic mechanics of armor piercing. However, there is one thing I am not clear on.

If I trigger an ability like Ulzaad’s Decree which add a flat physical damage bonus, and I have a weapon with 50% armor piercing, does that piercing damage conversion only apply to the inherent physical damage of the weapon itself, or does the externally added flat physical damage bonus get converted as well?

Also as an aside, since an ability like Ulzaad doesn’t specify which weapon deals the physical damage, does that mean both weapons deal the flat damage bonus if I am dual wielding?

Armor Piercing is not exactly the same thing as conversion, it functions differently. AFAIK it is applied last after all other conversions. Not sure if it works with ANY source of physical damage, in the case of Ulzaad it will just give physical damage, the physical damage doesn’t become armor piercing until you attack. Not totally sure but I think armor piercing will only apply if you have weapon damage on an attack or skill, not on all sources of physical damage.

Flat Physical damage added to your weapon is also converted via Armour Piercing if it is not converted through other means of conversion first. So yes, the Physical damage bonus on Ulzaad’s Decree will be partially converted to Piercing damage if you have a weapon with 50% Armour Piercing.

See I thought that initially but

According to this, the flat damage from ulzaad DOES get converted, even tho the skill doesn’t specify a % weapon damage added to the skill or anything like that. That’s frustrating, vecause I was considering sacrificing ulzaad for ghoul to get that sweet, sweet ADCtH, but if it gets converted I’m not sure I want to give up that nice ability for my pierce damage-based build.

It doesn’t need to? It adds flat and % damage in the same fashion as say Flame Touched or Iskandra’s Elemental Exchange. It’s just that Ulzaad’s Decree is a timed buff instead of a permanent toggle.