Since today my merc keeps changing his aura based on difficulty.
I choose holy freeze from nightmare, but as soon as I join a hell or normal game the aura changes to defiance. This is also present on different characters with different mercs and different auras. Anyone else facing this issue?
Even restarting the game does not solve the issue.
Yes, and it looks like an unpatched bug
Its only a display bug in the mercs inventory.
Aura should stay the right one.
Odd. You might be correct. Still before the post I noticed the missing of the aura and he did not activate it. I am not sure if he needed even more time to activate it. I will check if the issue happens again.
Got the display bug aswell, but the aura is the right one, once in game and fighting my way through these demons 
Glad I wasn’t the only one to notice this. I think their auras’ are very misleading though. People will just assume that the mercs’ aura will be active 100% of the time. However, it’s active very randomly. I went to chaos sanctuary to test this out and my merc only had his aura active 5 times. x2 on the way into chaos sanctuary, another x2 when killing the spawned elite packs before Diablo, and finally once more when facing Diablo.
The aura on a merc is very random on it’s activation and how long it stays active for.
I’m not complaining, just saying that’s all.
Afaik when once merc activate his aura it works all the time. You can see different auras swaping under you to show you every “buff” you got at once, but its not like youre losing your boost due to that. Merc aura however will not aply to you when youre too far. Low merc aura means you have to work close to him to have aura benefits.
And also you have to wait some time when you buy/revive a merc for his first activation.
Easiest way to notice its always working once active is to have tele soso with holly freeze merc and with every tele you will see the freeze effect on the enemies xD
and also yes - display of the auras youre merc is using is bugged in his info when you jumpin to other difficoulties. Yet he will always have the same aura that you choose when buing no matter diff. (rip my english and your eyes)