I think a sizable portion of the community feels that dark knight is in serious need especially in light of the proposed warrior party utility. General consensus seems to be dark knights have less utility, damage, and mitigation compared to paladin and warrior. I think the mostly everyone would agree with the following suggestions for dark knight, though only some subset of what is below would be considered reasonable buffs all of them might be a bit much:
1) Shadow Wall needs either a 2 minute cooldown or it needs an additional effect to justify the 3 minute cooldown
2) Dark Passenger needs either a potency increase or a mana reduction or both, the cost of this skill is too high for what it does and is out of balance with the rest of our AOE.
3) Delirium is too long a cooldown, it should be reduced or enhanced
4) Sole Survivor needs to be revised
5) Dark Knight damage is too low compared to paladin and warrior against single targets
6) The healing part of soul eater should be taken out of grit
7) The Blackest Night needs to last for at least 6 seconds
8) Increase the potency of Bloodspiller when not in grit
9) Dark knight needs a full party utility
10) Make Living Dead less healer dependent
11) Dark knight needs more mitigation, but not more of the blackest night
12) Blood Price seems really weak against single targets, people want an additional effect
13) The pay off of the blackest night compared to the risk in using it is too low
Some suggestions some made by me some made by others about the above that have less universal agreement but seem popular:
1) Sole Survivor should act as a party resource refresh turning party damage into party HP and MP to give dark knight party utility
2) Increase dark knight resource generation by making blood weapon and blood price a 30 second timer
3) Increase the effects of delirium either doubling the effect of blood weapon or blood price, or doubling their duration
4) Take the party mana refresh canceling effect off dark side so dark can also benefit from bard refresh
5) Make dark mind mitigate all damage, understandably the timer might go up or the mitigation come down a little
6) Add effects which reduce the cooldown of other abilities (dark arts reduces the timer on delirium, Bloodspiller lowers the cooldown on carve and spit and so on)