So I've been noticing a darkening bald spot on my Mals back. Kept his collar off for the past couple days but haven't seen anything get better.

Looks exactly like something that showed up on my Shiba Inu's head a few months ago.  Almost three weeks of twice a day Neosporin rubbed in well with my finger did the trick.  USE YOUR FINGER, q-tip or swab is too abrasive.  Most likely a bacterial infection.  Could possibly be fungal, which would be treated with an over the counter anti-fungal cream like Tinactin.  Just don't be surprised if it takes a while for the hair to grow back.  The spot on my dog was a little over one centimeter across.  That appears a bit larger.  I'd go with the Neosporin first.  Be sure to use the regular Neosporin, NOT the one with pain reliever added.

Note:  Be sure your dog cannot lick the area if you use these products.  Otherwise, perfectly safe.

Has there been any behavioral changes?  Drinking more, moods etc.....

Hair loss was the start of our battle with Cushings, hopefully it's not...

My Mal was misdiagnosed for fungal infection until the behavior changes....

Negative. No mood of behavior changes. I'm going to give the Neosporin a shot and see what happens. Hopefully he just got an infection from an unapproved adventure.

I'm dealing with the same thing with my Akita. I found a bald spot close to her tail and the next day, she had another bald spot the size of a fist. She also has the black spots and everywhere there is a spot, there is a scab and hair falling out. Took her to the vet and they prescribed Ketoseb +PS mousse and Cefpodoxime tablets. The vet was on Friday morning and she's gettin better now. Good luck OP.

My Dogue De Bordeaux had an issue that looked like that we where told it was skin mites. Vet said to change his diet and that was all it took. My understanding is that all dogs carry skin mites but their immune systems keep the mites in check.