Compared to Ryze who was hurt by the conversation, Edward has his mind elsewhere.
At first, he hadn't paid that much attention, but now he sensed a familiar presence, much like the one he had sensed inside the Executor's castle before discovering the mark on the Executor's bed chamber door handle that he found odd.
It was as if something invisible, something beyond the naked eye, was watching him.
Glancing to the door, he pondered in thought.
'Rex is still outside, still hasn't come back yet. So I'm right, this has to do with him'
Edward's suspicion grew stronger because of this, and he couldn't shake the feeling that this strange presence had something to do with Rex. If it were a spell, there would be traces of mana, but the presence he felt was entirely different.
For all he knows, Rex has the capability to do this.
Soon enough, the presence suddenly disappears and vanishes into thin air.
Clack!