He smiled, somewhat elated that he'd be seeing her again, though how well she thought his power worked, well... While it was true that he could detect auras, he hadn't developed the skill to detect an individual's aura without some kind of specific catalyst or mark on them; that being said, an idea struck him.

"It doesn't exactly work that way but..." he sensed his surroundings a moment, when feeling safe he said, "this is probably gonna gross you out a little, but this is the only way I can do this."  He grabbed his small book and opened it up to a blank page, turning away from Grace's sight, Kyle bit down on his thumb, hard enough to draw blood.  He made a small grunt at the sudden pain, but powered through it drawing a small sigil of blood on the blank sheet.  Placing his hand over the sigil he whispered a small incantation, it glowed briefly before fading away.  Turning back to Grace, his finger pressed into his thumb to cauterize the wound, a small puff of smoke escaping.  Ripping out the piece of paper and folding it, he explained himself, "I just made a tracking sigil, its linked specifically to me, so only I can sense it, with it, I'll be able to find you."

He frowned slightly, "I know its gross and...really, really strange so, you don't have to take it if you don't want to."