Arcane Fury, Multiplicative Or Additive?

[(PSN)QuantumEntangle]

I've been trying to find out if Arcane Fury's 40% melee damage is multiplicative or additive off of base damage or if it works like Madurai IPS passives by adding the damage percentage after base X mods.

Seems to be no interest or testing done anywhere, the price for each is a massive 200-250p each so I'm wondering if this is all rarity based or is the price justified because it's 40% additive after total damage is applied?

Any info or a link to test results would be greatly appreciated.

[TARINunit9]

If it's anything like the rest of the game, it would be additive

[(PSN)QuantumEntangle]

Yes I hear you but the real question is, additive off of base damage, like adding an elemental with 40% damage which works off the base weapon damage.

or

Additive to the total damage after mods are applied like the Madurai passives, in which case the price would be worth it. It's a huge difference.

Just trying to clarify before spending the plat, especially if it's garbage if the first option is what's true.