But really?? Who would be using this as a way to cap def other than a new tank that is only doing herorics? IDK about you, but I use def as one of my primary avoidance+mitagation stats. Def not only give the best avoidance per stat point + it gives us more dam reduction on IBF.
Bottom line though, I would not let a DK tank in any 25 man that was using this to cap def. If you "need" the sigil to cap def, then your not geared enough. Now if your floating the line with gems or chants, then I still wouldnt let you tank because you dont understand the basic premise of what a tank is. Tanks are there to mitigate, avoid, and smooth out damage intake. leaving yourself, even if for 1 or 2 swings at the start of the fight, to a crit is not right IMO. If you really want to take that chance, have fun, but when you get crit and killed and wipe, even if its monthes from now, is it really worth it?
I cast the spells that make the people fall over.