http://forums.elderscrollsonline.com/en/discussion/202926/blood-knight-pve-nightblade-tank-pre-ic/p1

This is my old thread. I still use most of the skills but here's a quick run down. I'll also add the gear I use.

1st bar: 1h and shield
Strife--Swallow soul, for extra heal
Drain power--Sap essence, ae damage plus heal
Low Slash--Heroic Slash, inflicts minor maim and ultimate regeneration (important)
Siphoning Strikes--Siphoning attacks, now a buff with a cost but you still need the regen
Puncture--Pierce Armor, taunt plus big debuff
Ultimate: Meteor--Shooting Star, this will be your pull. Use it in place of Soul Tether once you earn it. The big area, knock back, and damage makes for a great pull. Plus shooting star earns you 9 ultimate per enemy hit to be used again quickly.

2nd Bar: 1h and shield
Teleport Strike--Ambush, your gap closer, stun, and empower granting ability
Entropy--Degeneration, use this as a mild dot but more importantly to gain health while attacking.
Path of darkness--Refreshing path, alkyd heal that now sticks to you for 3 seconds when you leave it. It also procs your shadow barrier passive to raise your armor for 11 seconds (full heavy armor)
Grim Focus--Merciless resolve, 8% damage boost that will increase power of strife and other abilities plus gives 10% stamina regen.
Bone shield--Spiked bone shield, your only real damage shield. Most damage is physical and this skill is good for that.
Ultimate:Consuming Darkness--Veil of Blades, 30% damage reduction is pretty good, but you will need the damage version for a few fights in particular to help you pull while mitigating damage. All around very useful.

More importantly though is the gear. Most tanks ran with hist bark and whitestrakes before the patch. Throw that trash away. Your new main set is Willows Path. It is a 6 trait set that grants a bonus to recovery in each resource and health. The 5 piece bonus grants 15% regeneration during combat. This bonus will stack with your natural 15% regen as a Nightblade from the shadow passives.

Your second set is Song of Lamae, a 5 trait set that will grant bonuses to both resistances and max health. The difference between the previous sets and the new ones you should wear is less health recovery. However, your abilities will supplement that and your healer will pick up the slack. I also wear full heavy armor and each piece has additional armor. Armor rating is a 1 for 1 to both resistances so use the additional armor trait on all pieces. Some might say this is overkill, but I never met a group that liked squishy tanks.

For jewelry get 3 pieces of unassailable for extra health and healing taken. Put magicka recovery on two of them and stamina recovery on the third.

Spec your attributes to where your health and magicka are nearly even in points spent and adjust to your preference. Put no points in stamina.

Be sure to make some food, or have a friend do it, that offers max health and stamina. The food bonus helps make up for your low stamina/high regen build.

Check out my old thread for what to do in lower levels as this is more of an end game build. This build has a focus on regen to make for a few nerfs from ic.Groom focus may be substituted by something else depending on the situation. For example, switch it to dark shade (the ranged morph of summon shade) while fighting the engine guardian and its attacks (fire balls and poison gas) will help keep the group alive and you out of harms way to debuff him.

Edit 1: I no longer use relentless focus and I have switched back to Whitestrakes/Willows. I now use mass hysteria. Read on to know why.