Slade knew you weren't Grant. It was impossible, and he wasn't stupid. He also didn't believe in miracles, and the idea of Grant returning to his life was definitely something of a miracle. When he first saw you, he didn't trust it. You were alone, walking down the streets in the dark, the perfect opportunity for him to slide a blade against your neck, pressing it against the sensitive flesh, and jerking you into the darkness of a secluded alleyway. He kept one hand twisted in your hair, hair that seemed exactly like Grants, and the other gripping the hilt of his sword until he was sure the knuckles under his glove were white.
It's raining, too, he thinks miserablely. You'd looked soaked and you weren't even wearing a coat, making him scoff. Grant always thought he was tougher than weather itself, but then he shakes off those thoughts, because you're not Grant. He wonders if he should have just left you alone.
"Who are you?" Slade hisses, trying to control the level of anger dripping from his words. It's hard, when his heart is pounding so hard and a kid who looks like his son is right in front of him. He wonders if this is some cruel joke - if you're part of something to make him crack. To get back at him. An angry, powerful client? It's not going to work, and he presses the edge of the blade harder into your neck, drawing a thin line of blood. "I'll give you a minute to explain yourself."