Since there was no escaping the Harbinger, Elias made up his mind to do something drastic. It was something that even he would've advised himself against if he had any other choice.
Instead of running in the other direction, he started running in the direction that he had come from, going back toward the Harbinger.
Even as the surroundings were shrouded in a cloud of dust, the Harbinger could see through everything clearly. After she had cut the Beast of Decay in two, she started paying attention to Elias, who was trying to get away.
She wasn't in any hurry to catch Elias, as she wanted to give him some hope that he could escape.
Only when he was filled with hope could she crush it beneath her feet, just like the students of the Dimensional Academy did. She had no pity or sympathy for a child, as all of them were the same kind of people to her.