I've noticed a lot of builds posted for Shadow's Mantle that don't seem to include any way to offset the expense of heavy Impale usage. Most people seem to focus on getting CDR for Vengeance, including chucking Dawn in Kanai's Cube. Many don't even use Karlei's Point preferring to equip Lord Greenstone's Fan for the FoK buff. I can see the advantages to using Vengeance, but how are people affording the cost of a set that relies on Impale? I'm finding I frequently run out of hatred.
Fok Builds are not viable because the shift in stats/gear/power items makes it extremely hard -if not impossible- to survive beyond 65-70. A few people achieving high results with fok build are exceptional(y good (and stubborn! ;D )) players.
It has slightly different play style than KP builds;
-With Fok you need to gather as much progress monsters as you could and blast them with well timed FoK shoots.
-In KP, you ignore anything around you but yellow champions and blue packs. Meddling around large packs or remaining yellow minions is inefficient most of the time.
-KP build can double dip in toughness -if you can figure out to keep your hatred above 85-90% most of the time- by being able to ditch "seethe" rune and utilize dark heart rune via skill. So Armor cube slot becomes free, and most beneficial power item to replace Visage of Gunes is Aquila Cuirass.
-There's no way of getting away from vengeance or doing anything which compromises its uptime so do not even bother..
Here's my current setup which I use to consistently farm gr 70-80. This is one of the most tanky builds for a DH. With a few changes it is also great for TXIII bounty farming. UE multishot is still the best option for nephalem rifts.