"You caused it?" Alden looked at him, confused. "That is part of my training?"
"Yes," Aether nodded. "What you experienced was my killing intent. Your body trembled because your senses felt the dense killing intent and felt the approaching death.
They were warning you to run away. They were warning you that someone has the intent to kill you."
Alden's eyes were wide in shock as he listened to Aether.
"The killing intent is trained on the battlefield. With the numerous kills you accumulate, you will learn to release your killing intent consciously or unconsciously.
I can't help you with the killing intent. You can only obtain it on the battlefield. There are also times when one obtains a killing intent through intense emotions of anger. This killing intent is stronger than ordinary, but it's rare.