Works ok for me I think but I don't have the survivability of some Templar tanks I've seen... not sure if that is my ineptitude or my current level (VR6).

Armour/weapons:
5 pieces Whitestrake's Retribution
3/4 pieces Seducer
5 light, 2 heavy

Line 1:
Sword and shield
Solar Barrage
Explosive Charge
Reflective Light
Absorb Magic
Blazing Shield ^^

Line 2:
Restoration staff
Healing springs
Breath of Life
Extended Ritual
Annulment
Unstoppable

Both ultimate slots Solar Disturbance.

I have survived the initial burst from single VR12 NBs and then killed them.... but there is always the chance they were just crap and didn't know what they were doing after not killing me in 2 hits.

I have also faced down a Sorc of the same level as me and killed him and gone toe to toe with a VR9 DK who with 1/3 health left, fell backwards off the keep wall and killed himself, so I don't know how that would've ended.

I cannot, however, survive 2 co-ordinated VR9+ attacking me and I certainly cannot run into the middle of a group of 10 and last more than 5 seconds, as I have seen some good DKs do.

Probably not much help since I am not sure how good this will be at VR12 and I'm not a 'pro'.. but it is a fun build to play and sometimes I'm surprised how well I'm doing...

...until I die 1 second later.

I run a Templar tank PvP like this :

Armor 5 heavy, 2 light, 5 seducer, 4 torug
Weapon 1 : shield
. Invasion (shield charge)
. Biting jabs (just as a finisher after a stun
. Blazing shield
. The aoe Templar thing
. The blocking buff that can return an attack and stun
. Ulti the spear one that gives a damage mitigation

(sorry i don't remember the name of comps)

Weapon 2 : destro staff
. Reflective light
. The 3rd attack of destro
. The stamina regen buff
. PPurifying ritual
. Inamovable
. Ulti : the mage guild that gives Ulti points.

Works pretty well in any situation (group, solo, keep def)

Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield->Blazing Shield...

Get it? I know the rotation is complicated.