While you do have to pick up the pace in the Demon Halls due to the spawn rate (especially floor 24, dear god) you can’t just skip them. You need to explore for… reasons. And not just for the 3 upgrade scrolls and 2 potions of strength.

As for Evil Eye’s, you get 2 turns once they start charging, sometimes more if they are chilled. Only fight them when you are near cover and can duck around a wall. It does suck to get blasted from the shadows. Buy all the torches you can.

Make sure you don’t let a ripper demon jump right on you. The bleeding causes so much damage! Other than that, they are pretty squishy. Even if they are in the shadows, the game warns you they are about to leap and flashes a little target on the floor for a second. Try to step away from the target.

The succubus will teleport to you and get a free attack (it has a cooldown, though), but if there is only a single tile between you, she will just step toward you. So if you’re kiting her with a Ring of Haste or she’s chilled, don’t get too far away. And if you have primarily ranged attacks and she’s sleeping, you’re often be better off walking one tile away from her before attacking. You only get one unanswered attack in that case (if you don’t have haste), but that’s actually better than being attacked the instant you wake her. She also has a max range, so if you can attack from very far away, that’s better than everything I said, but that always seems rare.

Save Scrolls of Magic Mapping for the demon halls. They are super good there.