backgroung:
every champion and rare pack has soft enrage on inferno where after 4 minutes u start getting increasing dmg while being in sight range of any of the mob from the pack (can be outranged)
after another 2 minutes there comes *hard enrage* where whole pack just resets health to full
as everyone knows u can reset enarage on mobs and their health by staying out of their aggro range for long enough, however those timers are not tied together
generally enrage resets after around 15 seconds, their health resets after around 25 (values not measured, i dont have a working watch at home lal), so theres this ~10 seconds window in which u can approach the pack and continue fight - can be done multiple times of course
reseting of timer works before they actually hit soft enrage also