[FIXED] [Death Knight] [Unholy] Tak'theritrix's Shoulderpads and Dark Arbiter interaction

[CyberKing]

WoW Freakz spell link: https://www.wow-freakz.com/spells.php?spell=207349&&name=dark-arbiter
Bug description: Well as the title suggests the problem is when you combine these 2 spells/items together. Here on Freakz Tak'theritrix's just adds 40% dmg on DA, if you have lets say 100% base dmg on Arbiter and you cast 10 Death Coils (each gives 45% dmg increase) which is 450% and you add it on base it becomes 550% activating shoulders just adds extra 40% making it 590%. This all sounds logical and normal but when you compare to Retail these numbers just dont work.

Let us take this https://www.warcraftlogs.com/reports/bjQnzhD3mNWLZCKT#fight=3&&type=damage-done&&source=20 guy for an example. He had 13 casts of Death Coil in burst. His highest hit was +3.6mil (the crit was +7.2mil so u divide it by 2 and you get +3.6mil) And so i went ahead and tried to get roughly his DA dmg without any DMG modifiers. Lets take his 2nd cast of DA where you can see that he has all the buffs so you know that it will be the same base DMG for the end of the 1st cast because there he has all those buffs aswell. So looking at it, the minimum hit on start of that 2nd cast is 630k and this was when he had 1 Death Coil cast which is 45% DMG inc. So when I remove that 45% I get around 434k. And then lets try to increase this with Death Coil % and Tak'theritix's. On Freakz its going to be 434k x (585%+40%)= 434k x 6.25= 2.7mil which is nowhere near his highest hit. And then what I think should be happening is that shoulders are multiplicative instead of additive. If I take that 585% x 1.4 I get 819% + 40%(from base) I get 859%. 434k x 8.59 = 3.728mil which is almost perfect, a bit over it but compared to the previous result its nowhere near 900k vs 100k difference.
I have made these calculations on several other people from the Logs aswell and the multiplicative way is always around those values while the additive is never near.
The only mistake here I could have made was that he got 2 Death Coils instead of 1. Which is 90% instead of 45%.

Or the problem could be somewhere at the start I guess? https://imgur.com/a/EveOR7J my recount from Freakz where I Use DA and throw 1 DC 505979 highest hit which is around 350k base. And I have the same mastery as that guy a bit more actually the only difference in my test was that i had 2k STR less (had potion, Unholy Strength and Concordance also)

Proof: This is all I could find about the Shoulders are they Multiplicative or Additive and also https://www.icy-veins.com/forums/topic/21911-unholy-death-knight-73/page/18/
A guy on there, around the middle of the page asks the same Question and he gets the next reply:"You'll need to test this manually, tbh. It's not released anywhere as actual information, so we're a bit screwed on that front. You can test it with DA as an additive/multiplicative test. The shoulders are BiS only for DA, not for any other build, so that's worth keeping in mind".
Thanks for reading hope you find out what the problem is. Thank you.

TLDR: Shoulders should increase the Total DMG of the DA, meaning both base and the DC increase.

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