The Necklace of Heaven was a powerful Holy Artifact. After Noctuna activated it, the injuries of the soldiers of the allied army started healing. They began to fight back with more ferocity which forced the Underworlder army to steadily retreat.
Aethelwolf and Empress Shiphra also joined the battle. They specifically targeted the strongest Underworlders. Their presence decreased the pressure on Ramiel and the other experts.
The lion-headed Underworlder was quite strong, and even Aethelwolf was forced to use his strongest skills to fight him. They battled for over five minutes before the lion-headed Underworlder fell under Aethelwolf's sword. His severed head rolled on the ground, shocking the Underworlders who had witnessed his death.
"The leader is dead! Let's retreat!"
"Retreat!"
The remaining commanders of the Underworlders immediately commanded their troops to retreat after the death of their leader.