ok I am referring to death strike, in pvp it heals for a rather disgraceful 20% of damage taken or 5% of total health.
At 5% this now takes 6 death strikes to equal a single impending victory which heals for 30% of max health for 1 global and 10 rage.
Death strike will cost 210 runic power and 6 globals to do what is achieved in a single global by a warrior.
Now some simple maths, assuming you recieve 10000 damage within 5 seconds somehow, thats about half of a decently geared players health, you will recieve a mere 2000 health back thus you require 5 globals just to reverse the damage and 175 runic power.
To iterate, that is 7 frost strikes worth of damage which in the current state of balance would not actually even deal this much damage meaning you simply cannot choose to overwhelm your foe using damage as opposed to healing.
Thus there is simply no option that can be chosen in which a frost death knight will ever be able to win in a reasonable fight under this nerf.
To further this, even at a whopping 50% buff to frost strike, the frost dk will still not be able to come close to a beast master hunter in terms of damage for example