The idea of the build would be to taunt a targeted enemy (preferably a damage dealer) so the enemy does 50% less damage to your teammates then you disappear with cloak. The Nightblade class also has a lot of great utility skills that aid with defiling the enemy. Ideally, you'll want to use your supporting skills first, then drop the taunt and disappear. These are some preliminary thoughts, and I'd be interested in hearing what others might add to this idea.
5 Piece Vanguard's Challenge - Chest, Legs, Necklace, Ring, Ring
(2 items) Adds 1064 Max Health
(3 items) Adds 1064 Max Health
(4 items) Adds 4% Healing Taken
(5 items) When you taunt an enemy Player, they deal 50% less damage to all other Players but 100% more damage to you for 15 seconds.
5 Piece Seducer - Feet, Waist, Gloves, Shoulder, Destruction/Restoration Staff
(2 items) Adds 129 Magicka Recovery
(3 items) Adds 967 Max Magicka
(4 items) Adds 129 Magicka Recovery
(5 items) Reduces the cost of your Magicka abilities by 8%.
1 Piece Shadowrend - Helmet
(1 items) Adds 129 Magica Recovery
Skills
1) Inner Rage - Your most important skill because it taunts enemies from a distance to trigger the 50% damage reduction.
2) Pulsar - 10% health reduction.
3) Lotus Fan - Speed reduction.
4) Piercing Mark - Prevents enemy stealth and drops their defenses.
5) Mirage - More defense and dodge chance.
6) Dark Cloak - Grants you 8% less damage taken and you disappear.
7) Manifestation of Terror - Create fear traps on the ground to protect yourself if detected (enemies can't see the traps).
8) Shadow Image - Further reduces enemy damage and allows you to perfrom defensive maneuver of teleport.
9) Crippling Grasp - Ranged immobilize and slow
10) Elusive Mist - great defensive escape when in a jam and cloak won't cut it.
Interesting Combinations
Inner Rage + Cloak = The bread and butter combo for defiling a target.
Bolstering Darkness Ultimate + Elusive Mist = 60% damage reduction and 75% damage reduction skills in case the taunted enemy targets you.
Manifestation of Terror + Shadow Image = Control over areas while protecting yourself and adding maneuverability.