It is quite a rough fight on tank's health. Hand of Purity and unglyphed Divine Protection will be your best friends. Get mutated while your Viscous Horrors are up, since there should be a nice line of pools behind the boss as he's moving around.
I found Long arm of the Law worked best for me with moving around, since you'll be doing so much of it. Speed of Light won't be up every time you need it. I liked Holy Prism to help out on healing, and bouncing it off myself with all the adds around me was quite useful, or off the boss to help raid healing. I can see why some would use Execution Sentence, but personal choice I guess.
But yeah... a nice fight for tanks. Just be sure to get those Viscous Horrors as they spawn, use lots of Purity and Divine Protection, get mutated, and backpedal a lot