After a night of bitter battle, the elves finally made it to dawn of the next morning. However, the demons were different from the undead. Demons weren't afraid of the sunlight. In fact, since the sunlight in the Mortal Plane was much gentler and soothing compared to sunlight in the Chaos Abyss, the demons instinctively felt delighted and excited.
Additionally, since both demons and elves had night vision as their natural talents, it was the same for both sides whether it was dark or light outside.