It has been held for a while now that Light/Flame/Aqua Gorgets don't have any apparent effect on Atonement damage, and a search hasn't shown any contrary or new information thus far. Being the curious person I am I did some testing of my own after receiving the weapon skill last week. I ran sets of trials using both Light Gorget and empty neck slots once enmity was capped. Target mobs were Decrepit Gnoles in Jugner Forest [S].
Once I was able to do a consistent 720 damage (soft cap at 100% TP) I did a series of Atonements between 100%-110% TP with both no neck piece and with Light Gorget equipped. The range is given due to random shield blocks or Joyeuse procs. As expected, with no neck piece equipped I would do between 720-730ish damage per WS. Now the interesting part: with Light Gorget I was doing a steady 750 damage every time. Even with exactly 100% I would do 750 damage. Damage never exceeded 750 however. So it would appear gorgets do have some affect on Atonement. The question is in what way.
The first reaction would be that the gorgets lower the TP% needed to exceed the soft cap on Atonement damage, but that can't be the case since that would be indicative of a TP Bonus and not the known fTP bonus of gorgets. What we do know is that it boosted damage at 100% TP and capped enmity by 30 points. It was then that I decided to see what happens when enmity hadn't been capped yet.
I do not have a table of values to show my work as I was gone the majority of the weekend after my initial testing, but this is what I found. I would engage my target with 0% TP with Flash > Sentinel > Rampart > Shield Bash > Reprisal > Cure IV for 374 > Flash, and melee up to 100% TP. Due to the randomness of melee hits and damage taken I can't be precise, but at this point without a neckpiece my Atonements would do damage in the low to mid 500s. Repeating the same process on a fresh target using a Light Gorget my damage would be in the high 500s to low/mid 600s. After a while the pattern seemed to be a roughly 10% increase in damage.
So to sum up so far:
- Atonement damage is based on TE + VE. (known)
- Atonement has a hard cap of 750 damage or 375 for both CE and VE. (known)
- Atonement has a soft cap of 720 damage at 100% TP or 360 for both CE and VE. (known)
- WS Gorgets have some observable effect on Atonement damage up to the hard cap.
- Damage increase appears to be roughly 10%.
That final point leads me to believe that Atonement has a fTP modifier just like any other WS with a standard value of 1.0, only it is multiplied against TE (or against CE and VE independantly, testing would be required to differentiate) instead of wDMG (D + fSTR + WSC). This would be in keeping with the known nature of WS gorgets and what I have observed. One strength of this finding would be for initial Atonements where enmity has not yet been capped.
What is the practicality of this information? Since Atonement is running double duty as damage and a hate tool, wouldn't a Ritter Gorget be more effective than adding a meager 30 damage at 100%? Running the numbers through Kaeko's formulas for enmity generation for damage dealt indicates otherwise. According to the results, given any base damage and base enmity level you will generate more enmity with the 0.1 boost to fTP than with the +3 boost to enmity.
Here are a few test cases using capped TE and a level 85 target.
Spoiler: show
Naturally as your TP brings you closer to the hard cap Ritter Gorget will become more effective, but when spamming Atonement at 100% TP you will generate slightly more enmity using a WS gorget for 750 damage than a Ritter Gorget for 720 damage. While it is a small enmity and damage increase, the cumulative effects over time may be worthwhile, and the damage boost to initial Atonements would be appreciable. Anyone who can also test to verify these findings would be encouraged to do so. At the very least I hope this was an interesting read.