The response time of the aura (Diablo 2)

Long time wondered this question. Zameteli that aura drops on mobs at different speeds. How it works , know Passed good fumbles in those parts of the game. The aura is a pre-cast timer ? Supposedly works on new mobs within the area of the aura. Zameteli the first wave of BR , they padout already with an aura that takes a couple of seconds before going to work. And I understand that it does not affect , and whether all the auras this timing the same ? Like this timing can be seen in the auras like Holy fire. And a second question , how much of aura rests on the mob already outside the area , for example Conway. I'd like to understand the mechanism of