He seems in between. In season one he was a villain, now he’s more (lack of a better phrase) anti-heroic/anti-villainous. Someone with a morally grey area.

Unpopular opinion, I really love Brenner and don’t hope he dies.

I say currently he is in between

I hate brenner i hope he dies and burns in hell

It's a mystery for now. Like how the hell he survived the demogorgon attack. I want to know about that.

I think S4 really changed the way I feel about brenner

That is true

I thought he died

But I think in season 2 he told El that he was never gone from her

Since Martin Brenner did had a care for Ten it might make me think that he might have a care for Eleven.

In between, but leaning towards being evil. He isn’t anywhere close to being totally evil, though.

I just hope that later he doesn't end up betraying, because that's all the damage he did to Eleven (especially to his mother Terry Ives who damaged his mind by wanting to get her back)