Quick update.
It seems as though the angel has HLLE. It is only mild and seems too progressed to have happened within the few days I've had him. He was skittish before I got him and I only got real face to face look yesterday when I noticed it. It's not too bad, only a little above the eyes and only noticeable when viewed extremely up close. I'm not too worried, my water parameters are perfect and I'm feeding a variety of healthy foods. My only concern is tank size, although temporary, it may still induce stress. So, I've gone a little to the extreme and I'm allowing direct sunlight into the tank as I've read that helps and whatever algae grows, it'll be more food for the angel and blenny to graze on.