The beasts dodged or blocked them with earth magic while the Demons didn't budge and took the spells head-on. The shadow that comprised their body neutralized the darkness element whereas everything else simply went through them as if they were just illusions.
The moment the Demons charged at the undead's front lines, the green of their eyes moved to their hands, shapeshifting them into the weapons that the souls possessing the skeletons were more familiar with.
Be them a great ax or a kitchen knife, the emerald weapons took the undead by surprise, allowing the Demons to push the enemy's blades away long enough to break through their ranks and made their formation crumble.
Demons of the Fallen wasn't just a tier five darkness spell, it also mixed Spirit Magic to call upon the shadows that always followed Lith and to bestow upon them weapons.