Blood DK and Ward of Salvation

Hey all. I was in a raid group and i saw a Blood DK (geared - about 4mil HP) do 25mil dps burst damage with Ward of Salvation. 99% of the damage was ward. What tinkers would he likely be using, as when as what ability? Just spam Death Strike or something else? Also, would you wanna focus on Mastery for this build, or something else?

Something that got nerfed very hard earlier today.

Was there a 2nd nerf? this was after the first nerf 2-3 days ago.

There was a second one that went out today along with Slay.

I can sort of see why it was nerfed. Le sigh, now non-froggers will have an even harder time doing Heroics/mythics but lets see if the supposed nerfs to those were good enough.