It might also be something related to hit. Attacks seem to land less nowadays..

best thing to do is video it and analyze.

high dodge can make fireballs miss
if brand is not triggering u will see blue numbers of what they absorbed
maybe people have been putting weapons on aids due to BS

anyways, hard to tell with out recording it, since stuff happens so fast, and dmg ticks so fast.

My lvl 10 golis still hitting same dmg.

Буду писать на родном языке , так смогу более точно передать идею 

Есть подозрение , что существует невидимый параметр - "сила" аккаунта .
Этот параметр формируется на сколько сильны ваши герои и амуниция(предположим по 15 ).
Больше всего вклад в "сила" сейчас делает "Просветление".
Приведу пример как работает этот параметр: пусть у меня "сила" -20 , у моего противника "сила" - 100 , тогда шанс игнорировать моим клинком станет не 80% ,а 
80*20/100=16%...
 Это сделано для того , что игроки могли успешно сражаться только против игроков своего уровня развития ( и больше донатили ,чтобы пробивать более сильных)

I'm trying to notice a difference, but having a hard time seeing it. Maybe it is because of how many chances I get to one-shot people with all of the PG and GS skills I am unloading in the first 30 seconds between having Renee Ven and Ironclad.

I'm starting to believe more and more that Pan is the one who got nerfed. I'm getting 3-starred much more often now on defense. It's actually quite frustrating.

I think I have an idea of what's going on.

Enchantress aid now heals at each HP % interval even if dropped well below that percentage in a single hit.

Before I'd someone had an ET aid I think I could hit for 80% dmg and it would only heal once. Now it seems like it's healing for all the % blocks passed.
I just did a coli with someone and he had half my power. I hit his starting 3 wolf, AD, TS and after PG divine his TS had dropped for a half second and then was back to full.

Another possibility is wolvenfiend in human form. His dmg red cannot by mitigated by the brand and it seems like the dmg reduction he grants to allied heroes might also be unable to be mitigated. There is definitely a significant difference in the number of people using wolf now as compared to before.

If I remember correctly (reading somewhere) the usage of Tyrant's Brand was never meant to bypass the Berserker aid. That was a bug. It should only bypass the normal damage reduction (which you get by talents, weapons, etc.)