Vallyne - Flashfire - The Silver Order - The Harbinger - 82480 Damage - http://i.imgur.com/GTxapPw.jpg

Vallyne - SGS-45 Quarrel - The Silver Order - The Harbinger - 90% Hit Percentage - http://i.imgur.com/YCZcAQi.jpg

Our raid group runs 2 shadow tanks (I am one of them) also, and we've beaten Kephess just so. With that said, however, afterwards I analyzed the logs and found that our KWs do deplete a lot faster on Kephess sometimes, in a manner that is probably unintended and bugged. If you look at the log carefully, every time Kephess swings at you post-60% (pre-60% there are other mechanics that makes the log harder to decipher), he doesn't attack once, nor twice (despite being Marauder-like), but FIVE times. The same is true of Terror From Beyond's tentacle attacks too, but that encounter is much easier so it didn't matter much (you may have noticed you lose 1~3 KW charges typically every time the tentacles hit you. Similarly, my guardian tank alt usually gains 1~3 stacks of Courage per hit. Same underlying principle). See below for a combat log excerpt of the relevant segment, cleaned up and color coded + summary added for emphasis, showing only Kephess attacks and relevant defensive buff gains/losses. Here you will see him attacking 5 times every time, as well as some odd interaction with KW. This splitting a single attack into 5 smaller attacks under-the-hood is actually a smart thing Bioware did. Instead of giant single hits (e.g. 3458*5 = ~17.2k on my shadow after armor mitigation) that can kill 2-shot me with bad consecutive RNGs, by splitting it into multiple hits, it smoothes out the incoming damage and makes my defensive stats much more reliable. However, it interacts with KW in an unexpected way negatively, in that we can potentially deplete our charges in as fast as 2 swings (i.e. 10 attacks) in ~3s. See another log excerpt below for this exact scenario, Both log excerpts also point to another weirdness, in that I lost all 8 charges of KW but only have shielded 5~6 attacks. These are not singular examples, in a couple other instances I've looked (on my Kephess and TFB logs) I would lose KW buffs after only shielded 5~7 times, all less than 20s after I gained the initial buff. However, I must also point out that in one instance I did find I shielded 9 times before losing KW, and the 9th attack was in the 3rd set of 5 attacks, so I should have lost the buff between the 2nd and 3rd sets of 5 attacks. This may again be a latency issue, but that means >1.5s delay in logging, seems excessive. Unfortunately I have to do these log examinations manually, as I don't have an easy automated way to extract the info with some sort of custom parsers. But if anyone has the ability to do so, I encourage you to check your logs accordingly to see if the same applies to your shadow/assassin tanks. Or if you can make a parser to do so, provide it so others can utilize the tool to check too. Regardless, with my shadow tank's stats, not counting shield overcharge, stim, or CDs, the difference of 20% KW shield chance (4-set bonus) is fairly significant on NIM Kephess fight, because he hits so much harder/faster. On average I would take 13% more damage from Kephess' melee attacks post-60% (all kinetic) if I didn't have KW up. This bug should not apply to Vanguard or Guardian, because their defensive buffs are time based, not charge based. In fact Guardians may actually benefit from this and gain their Courage stacks much faster or more reliably (if spec into it), resulting in cheaper Force Sweep & Bladestorm (tested to be true on TFB, but I have not tanked Kephess NIM with my Guardian alt yet). Of course Shadow tanks are still viable on Kephess NIM, we've done it with 2 shadow tanks in fact. However, this observation might explain why Shadow tanks do feel squishier on this fight and some other fights. I do believe this is most likely unintended, and thus probably a bug.