Would love to hear for other Nightblades on this I will be focusing Problem power, morphs and passive. Just to get this all in one place.
Assassination skill line: A
A1 - Ultimate Death Stroke morph Soul Harvest: the bonus for killing while slotted randomly don't apply if you kill with the power it self more of a random bug report
A2 - Assassin's Blade morph Killer's Blade (stamina): deals magic damage and Physical Damage meaning that your stamina build using the Champion System to buff Physical damage will never matter here as it's magic damage
A3 - Teleport Strike Morph Lotus Fan: this power is so bad players really leave it as Teleport Strike unmorphed and here why the DoT damage is only better if you hit 3 people other wise hit Teleport Strike 3 times is faster and better damage somehow. Also the power can't use the passive Master Assassin as it can never hit from stealth for whatever reason.
A4 - Blur Morph Mirage: this power is great as is, but a minor buff to both Armor and Spell resistance will put it on par with Double Take but again it's not weak or broken so not big deal just a thought.
A5 - Mark Target morph Reaper's Mark: with 20% higher health return and Weapon and Spell buff don't know why this power gets so little use don't want to make it OP but something needs to be done here not sure what Honestly but Nightblades that run it feel free to chime in
A6 - Passive: Executioner: 1428 magica restore over 6 seconds after killing with an Assassin power is a weak return more so if your Assassin powers are the Stamina morphs cause you get nothing back
A7 - Passive: Pressure Points: 3% more crit per assassin power with so many powers and passives giving you crit in 1.6 this is no underpowered a change to a damage buff for both magic and stamina users would be far better
Shadow skill line: B
B1 - Ultimate Consuming Darkness morph Veil of Blades: the damage dealing morph to a once great ultimate with a lack of class shields the 60% damage reduction was a God send this was remove to only give 30% to the caster in return for a group heal (that the caster can't get) this is wrong as Consuming Darkness has a healing morph if healing as a focus, when I use Veil I never see people go invisible so they are not using Slip Away so no healing anyways
B2 - Shadow Cloak and all morph do we really need to say this no? ok great
B3 - Path of Darkness and all Morph: so background if you don't know the power could only be seen by the caster and don't pop you out of stealth when casted it was a great speed buff and did it's job now damage was not it's focus however damagve that can't be seen needed to be change but now you pop out of stealth and leave an arrow leading to you as well as the damage and heal being so weak. This power I get the way it was made was unbalance but now it's just not worth the slot a change to Lighting form would be better cause as I understand why the change was mode it has made the power useless for it's intention.
B4 - Summon Shades and all morphs: the four second debuff is great but their are powers the apply the same debuff for longer the last for 20.7 seconds at max but after four second they use light attack so only useful to drain stamina on a perma-blocker.
*Dark Shades debuff don't stack on it self as only one debuff of a kind can be applied but the power has a double debuff

Passives are great as is
Siphoning skill line: C
C1 - Strife would love a stamina morph to this Swallow Souls being better should stay magic but Funnel Health (Physical damage, please killer's blade this) would be great as it heals based on 25% of damage done this would add a Rally (Strife heals for the same amount on a magic build) heal to Dual Wield, One hand and Shield and Bow
C2 - Agony and all morphs: this most hated of Nightblade powers a range Lock down that back be blocked for free, it breaks on damage and does weak damage even on a magic glass canon on top a 1.2 second cast time. It's not even a light attack over Seven seconds the Dragon Knight lock down is unblockable not sure on the cast time but really buff or just remove it's not useful and I really tired to use this power it's just so easy to counter and see coming
C3 - Passive Transfer 2 ultimate on damage with Siphoning one a four second cool down is so Underpowered buff the bonus or something it's just so lame you would have to Spam the hell of Siphon to even see the usefulness of this passive
Please add your feedback cause it's been a long time coming.
@ZOS_GinaBruno @Zos