Blood Sap frequently leads to aggro issues and sometimes tank deaths as there is no avoidance while in effect. This can be dealt with by death knights by using Icebound Fortitude. Not sure what other classes can do. Would like to add something about it since it seems to be causing unneccessary deaths.
Shadowstep, is the target random like with the mercenaries in Halls of Reflection? In HoR, they do return to the tank, but I've noticed DPS dying to this, but that's possibly due to being over 110% aggro.