Flying Blade: ranged dagger throw which then alters to a gap closer and increases weapon damage
Relentless Focus: crit damage increase with every light or heavy attack. converts to stamina arrow attack for high damage
Deadly Cloak: damage reduction cloak and shrapnel damage attack
[SPAM] Bloodthirst: quickfire five attack and hits for high damage on final strike, plus heals for % on damage caused
Ult: Incapacitating Strike: Strong ultimate attack, enemy debuff after strike, and stun if used on max
Endless Hail: AOE arrow strike ground attack.
Siphoning Strikes: Weapon buff that causes your light & Heavy attacks to heal + magicka Restore on expiration
Barbed Trap: High damage DoT that you can deploy under a mob
Dark Shade: Summons a shade for 18 seconds doing direct damage and damage reduction to enemy it is attacking
Resolving Vigor: Heal + heal over time
Flawless Dawnbreaker: Heavy attack plus DoT plus weapon damage boost
it is understandable that you will not have all of these skills & passives opened as you level...these are the goals to be able to base DPS. Some skills can be swapped out for other skills if you are soloing. Open your passives as you can. Get your Guild lines open so you can open those skills up for later
There are a few different ways to go on dungeon/trial sets. Common ones are Arms of Relequen paired with Kinras's Wrath, or Relequen/Briarheart, I feel the new trial set actually pushes out a bit more DPS as well as buffs the group a bit better.
Monster sets I would go with either Domihaus or Selene.
Relequen is almost a must have main set as it has a stackable DoT effect your light and heavy attacks.
Kinras's wrath is a great secondary set which increases your damage when you light/heavy attack 5x.
I prefer Berserking Warrior(Yokeda) personally for Bosses or fights where there aren't a lot of add deaths. But for trash fights, or busy fights that have adds fairly consistently I prefer Sul-Xan for the crit bonus
There are a few different builds you can do for beginner sets. This set worked very well for leveling through dungeons until getting up to CP160 and getting higher end gear.
Recommend going light armor w/ Medium or heavy helm
The Nightblade is a very strong and powerful DPS class. Nightblades can use stealth and quick damage attacks, or siphon the life of of an enemy and restore their own health and resources. With multiple burst abilities, DoTs, and an strong execute skill, they can be very strong in both magicka based and stamina based aspects of play.
Mundus stone: The Warrior
Assasination: Master Assassin | Executioner | Pressure Points | Hemorrhage
Shadow: Refreshing Shadows | Shadow Barrier | Dark Vigor | Dark Veil
Siphoning: Catalyst | Magicka Flood | Soul Siphoner | Transfer
Medium Armor: All
Heavy Armor: Situational. For Magblade I don't find it useful outside of PVP
Bow: Long Shots | Accuracy | Ranger | Hawk Eye
Undaunted: Command | Mettle
Potions: Essence of Weapon Damage
Food: Lavafoot Soup and Saltrice
Master-At-Arms - 50
Deadly Aim - 50
Fighting Finesse - 50
Thaumaturge - 50
Rejuvination - 50
Bloody Renewal - 50
Boundless Vitality - 50
Spirit Mastery - 50
Use whatever you like in this tree