armor break + 100% p.pierce

does a.b and 100% p.pierce work together? if yes umm how? tia

 

It's simple.
Armor break is a debuff that "decrease" monster DEF,
While physical pierce is a stat that "ignore" the current DEF of that said monster.
What i said about armor break implies that it will decrease the DEF of that monster, and after that physical pierce will be taking effect into that current DEF of said monster thus making it work multiplicative instead of cumulative.
It also means that if you want to make the monster DEF fully rendered useless, you still need 100% physical pierce, either you use armor break or not.
Another meaning of it is that if you have 100% p.p then you dont need to rely on armor break since physical pierce wont go past 100% in the damage formula

 

It works together but doesn't increase your total damage output of said 100% pierce skill.

 

Pretty sure even if you use armor break on a boss, the damage of 100% physical pierce skill like Satellite Arrow would remain the same. It's because defense would be rendered useless, so no point in lowering it. I.e. 100% P.P. without Armor Break, let's say the mob's defense is 300, it'll bypass the 300, hence the damage of that skill would be calculated with the monster's defense counted as zero. If you use Armor Break, the mob's defense would become 150, and if you still use the 100% Physical Pierce, it would still be calculated with monster's defense as zero, thus making the damage constant no matter what. Although, I'm not entirely sure about this.