[Soapy]

The calculation is not only the same as every other skill in the game, but easier, since it scales on nothing but the damage you take.

Take x total damage.
Gain Narcus LV x.
Attack.
Deal (your normal damage).
Apply all on hit effects.
Multiply x by (100 - Fire Resistance)/100.
Multiply x by (100 - Magic DR)/100.
Multiply x by (100 - Overall DR)/100.
Multiply x by (100 + Hunted)/100.
Multiply x by (100 + Analyze Weakness)/100.
Multiply x by (100 + 1v1)/100.
Multiply x by (100 + Fire Weakness)/100.
Subtract Magic Armor from x.
Deal x as bonus damage.

Exactly. The same. As everything else.


Take 300 damage, gain LV 300 Narcus. With 10% Resist, 30 RES, Wraithguard, 1v1 (on the target only), and a whole 19 Magic Armor, that's still returning a third of the damage taken as a bonus effect.

Happy? I even used high reductions and everything. God forbid someone makes a 1.2k HP Narcus user and smacks a target that isn't stacking DRs for more than their max health with Plisfa EI.