How does threaten work?

How does Insight elemental resistance ignore work?

I dont know how it work, but it doesnt seem to work like Mercedes defense break. With defense break you will always do 808 dmg even if you dont have enough PDR to deal dmg in the first place, it needs futher testing and I dont know where to begin, seeing how its impossible to take insight off and lvling it takes too much time. Mines already capped, but dont think thats enough for testing.

Scratch that, found out why, I was having warrior character cards on.

I assume physical reduction works like the old pdr system but not entirely sure.