Horace Slughorn
Brilliant.
There was never a potions student better than her. She seemed to manage it with such carefree ease. Nothing phased her, nothing bothered her. She was the perfect student. Everything came easy to her.
She used to sit there, noting down everything I said, giving me her full attention. Sometimes she would chew the ends of her hair when she was concentrating hard.
She never ruined a potion. Never went to the hospital wing for a mistake of her own. Her potions were flawless. Perfection in liquid form. She had the greatest potential of any potion maker that I have ever taught.
Pity, really, that she was who she was.