To your question about FoK, You can make a better build with N6 in place of LoD. Lightning element, and a mainstream weapon that increases attack speed by 50% (yangs).
Does FoK damage standout after the accumulation of stricken @ 4APS, the short answer is no. Look at the ratio in the following two comparisons, in ALL cases the spender is doing more dps than FoK – sure FoK’s share might be larger in the second example. With today’s available legendary items, FoK is best for producing large area damage, not one-shotting rift guardians. You can collect trash and increase the damage but i wouldn’t count on this because the damage is low and you likely won’t see 2+ Quadrillion hits, which is abysmal damage every 30 seconds.
S6 Impale - defacto RGK
Here is some perspective, you can build FoK:Pinpoint Accuracy with S6 Impale Lightning, but nobody does this because the damage differential between the two skills is not big enough. Think about it, 30 seconds passes and you do 75+ attacks of impale, and one hit of FoK.
Impale: 75000% (S6) * 6000% (S2) * 375% (Karlei’s) * 3 knives (HPS) * 1.69 (Aughild) * 75 attacks = 8,263,307,812.5
FoK: 1600% * 6000% (S2) * 12000% (LGF) * 1.69 (Aughild) = 19,958,224
414:1 impale:fok
N6 Multishot build in Lightning – crap
Multishot: 360% * 14000% * 200% * 200% * 1.6 (double damage) * 1.69 (Aughild) * 90 attacks = 111,176,582
FoK 1600% * 14000% * 12000% * 1.69 (Aughild) = 46,132,944
2409:1000 multishot:fok
UE6 Non-Season / No FoK in Fire – okay getting better without FoK
Multishot: (360% + 600%) * 48220% (UE6+UE4) * 200% (Yangs) * 200% (DML) * 1.6 (double damage) * 1.50 (CC3) * 90 attacks = 901,767,168
N6M4 Non-Season / No FoK in Fire – we’re not close to Impale, but it’s getting there
Multishot: (360% + 600%) * 14000% (N6) * 200% (Yangs) * 200% (DML) * 1.6 (double damage) * 400% (M4) * 3 (sentries) * 1.3 (sentry %) * 90 attacks= 3,420,817,920
N6M4 Season 20 / No FoK in Fire – finally… something that rivals S6 Impale, but 1 extra jewelry slot makes S6 Impale the winner, unless you’re optimizing for attack speed (3.5+ APS), it’s very close
Multishot: (360% + 600%) * 14000% (N6) * 200% (Yangs) * 200% (DML) * 1.6 (double damage) * 400% (M4) * 5 (sentries) * 2.3 (sentry %) * 90 attacks= 10,087,027,200
Better make sure you have a zNec + zBarb