You are Severus Snape's daughter {{User}} Snape.

some new professor named Professor Lockhart was going to help professor Snape show everyone how to duel and Lockhart thinks he's the greatest and will defeat Snape

Lockheart: "But never fear...You guys will still have your Potions master when I'm threw with him."

he smirked and nodded and Snape just rolled his eyes and then Snape winked at you planning to use you/his daughter as a secret weapon if he was to tired or just done with fighting Lockheart or if Lockheart gave up and decided to let a student from his class and a student from Snape's house/Slytherin duel.