This is a, so far, my favorite class to play as. It is a full DPS stamina build suitable for both PVE and PVP. It is not the most sustainable class but oooh The Damage!
I use medium armor because it is a stamina build, it boosts your stamina and you will need that plus the passive skills. The two pieces heavy armor are there for health bonuses. It gives you the passives needed to sustain during a fight.
Note that this build is full dps, best played in group with healer or solo PVE. It is easy to get killed in PVP with this build, unless you attack first and have the element of surprise.
P.S. All of my builds are adjustable to your own playstyle. This is just a ”starters-build” to help you get a grip.
 

Armor:
5pcs Medium Armor
- Head
- Shoulders
- Hand
- Waist
- Feet

2pcs Heavy Armor
- Chest
- Legs

Bar 1 Offensive:
Skills                          *Morphs

Teleporting Strike       *Lotus Fan

Shadow Cloak            *Shadowy Disguise

Flurry                          *Rapid Strikes

Veiled Strike               *Concealed Weapon

Vigor                           *Resolving Vigor

Ult: Soul Shred            *Soul Tether

Bar 2 Offensive:
Two Handed

Skills                            *Morphs
Critical Charge             *Stampede
Uppercut                      *Wrecking Blow

Momentum                   *Rally

Reverse Slash             *Executioner

Aspect of Terror           *Mass Hysteria

Ult: Soul Shred             *Soul Tether

Traits on gear:
All 5pcs Medium Armor – Divines.
Both 2pcs Heavy Armor – Reinforced.
(For full Leveling-gear use only Exploration or Training)

Traits on weapons:
Bar 1 – Precise on both.
Bar 2 – Precise.

Glyphs on gear:
All stamina.

Glyphs on weapons:
Bar 1 – 1pcs Fire and 1pcs Shock.
Bar 2 – Fire or Shock.

Craftable Set Items:
Medium Armor – 5pcs Hundings Rage.
Heavy Armor – 2pcs Night Mothers Gaze.
Weapon Bar 1 – 2pcs Night Mothers Gaze.
Weapon Bar 2 – 1pcs Night Mothers Gaze.

Jewelry
I will not go into Jewelry because it is not craftable. Use the best available, for this build it is everything with stamina or health.

Attribute Points (50 points)
As this is a Stamina DPS build it is pretty clear that most of the points shall be put into Stamina. (This is not written in stone so do what suits your playstyle best).
42 Stamina
8 Health
0 Magicka

Consumables
Depends actually on what you are doing or with whom you are playing.
Solo PVP – Health, Food.
Solo PVE – Stamina, Drink.
Group PVP (no healer) – Health, Food.
Group PVP (with healer) – Stamina, Food.
Group PVE – Stamina, Drink.

Potions
Health and Stamina.

Mundus: The Warrior

Explanation for the choice of skills and spells:
Bar 1:
1. Teleporting Strike, who doesn’t want to able to jump through the air like Bruce Lee? Its a very effective skill that just must have as a stamina Nightblade. It does some magicka damage and stuns NPCs. If it is a player they are immobilized. The morph snares the enemies in the area and deals damage.