When I first joined Dominion, the role of Prot Paladin on Kaz'Rogal was to find a nice spot away from the raid and wait to die. I found this unacceptable. I took it upon myself to figure out a way to help the Raid and stay alive.
My first strategy was to get into a combination of my Shadow Resist and PVP Healer gear. This set gave me a large mana pool, and large hit point pool and a little Shadow Resist to maybe resist a Mark or two.
This strategy worked pretty well until the night we lost our Main Tank, and I was unable to pick up Kaz because I wasn't in tanking gear.
I had to figure out a way to survive Kaz in my tanking gear with a mana pool of around 6000 Raid Buffed.
I was talking to Cathmor/Baelor of Eye For An Eye. He explained some of the tricks he used as a Ret Paladin for surviving Kaz'Rogal. A Ret Paladin has it even tougher on Kaz because while he has about the same size mana pool, he constantly tapping that mana pool to do damage. I was able to apply many of those tricks to surviving in Prot gear.
The first thing I do is get a Judgement of Wisdom up on the boss. This helps my mana regen, and also helps our casters, especially our Hunters. Once Judgement of Wisdom is up, I use Seal of Wisdom and start hacking away with my Hammer of Judgement.
As soon as I have lost 3000 mana, I use a Super Mana Potion. The next Mark of Kaz'Rogal that is cast, I use Divine Shield to remove the debuff so it won't drain any mana.
If my Mana Potion cooldown is not back up by this point, I'll use one of my Dark Runes. These have been appearing with alarming infrequency on the Auction House lately.
Sometimes, I get lucky and catch a friendly bounce of a Prayer of Mending or a Chain Heal, which gives me a little mana from Spiritual Attunement. The only mana expenditure I make it to reseal Wisdom once it runs it duration so I can keep the debuff up on Kaz.
If I run out of tricks, and I see my mana is near 3000, I go ahead and run out. I do try to make sure I get that last refresh of the debuff before I run so it will stay up for as long as possible. Although, my number one priority is make sure I don't kill the melee group
Generally, he dies before I do, sometimes it's closer than others.