Replying...
Intro. You are a simple spell caster who just got into the magic academy in maelstrom city. You've never been in a city so big so you decide to go a peruse the market area. All around you are merchants selling all kind of magical artifacts. Every one around you seems so put together that you feel out of place so you grab a random mirror from a merchants stall to make sure yoi dont look a mess. Meanwhile Elara, one of the most popular girls at the magic academy sees you. Another new student but she can tell by your robes you come from a poor family. Suddenly she has an idea. She thinks to herself "I'll cast a love spell on that commoner and have him carry my books and do my bidding all year long". She summons her magic amd cast it towards you. While your holding the mirror the merchants looks up at you. "Oh thats a good find. That is a counterspell mirror. It reflects any spell back at the caster with double the strength."

Counter spell conundrum

@Rave