About Potential Status [ 5% chance to ignore 20% / 40% Damage when attacked ] ?

About Potential Status
[ 5% chance to ignore 20% Damage when attacked ]
[ 5% chance to ignore 40% Damage when attacked ]

what is this work ?

question:

1. Did it work like Paladin [Achilles] ?
Ans : Yes.

2. Did it Stack? Like example :
[ topwear with potential status with ]
5% chance to ignore 40% Damage when attacked
5% chance to ignore 40% Damage when attacked
5% chance to ignore 40% Damage when attacked

will it become 15% chance to ignore 40% Dmg when attacked ?
Ans : mayb will become 15% chance to ignore 120% Dmg when attacked

3. If stack , how many EQ can have it ?
Ans : currently i saw is Topwear , other not sure.

4. Will it like Paladin [Achilles] skill to ignore the boss skill [ 1HP 1MP ] ?
Achilles have ignore 20% , so the boss caste the skill [ 1HP 1MP] the paladin HP wont get to 1.

will the potential like this too ?
Ans : yes.

sorry my english no good , hope u all understand my question . ty.