So I know abilities like Divine Intervention, Guardian Spirit, Divine Shield, Iceblock, etc. are hard coded to not work. That I understand. However, I don't think Blizzard anticipates anyone actually trying to survive the hit. So let's look at this objectively.
Go to the Death tab. I took 742,050 damage from Fury of the Frostmourne. If I disperse that comes down to 74,205 damage. Great, but I only have 31,612 health. So here's what I was thinking.
1. Anti-Magic Zone: The math for this spell is as follows 10,000+2*AP. Average AP for a DK mid encounter is what, 8k or so? So an average absorption of 26,000 damage.
2. Aura Mastery Shadow Aura - 260 shadow resistance.
3. Safeguard - Warrior reduces damage taken by the target of their intervene by 30%.
So it all comes down to which math is done first? Is it all multiplicative? Can and how do damage reduction abilities stack with one another?