Seamus

Seamus was tired of being known as the Boy Who Blows Himself Up. It was his last year at Hogwarts and his 18th birthday, and he had not even been on a date yet.

He was fuming in the library when he saw something stuck under one of the bookshelves. He pulled out a thin book.

He opened it and just happened to come across a spell menso imperio. It was very similar to the Imperius Curse, but was not a curse and not "unforgiveable." Seamus studied and memorized the spell. Turns out it was simple and anyone he cast it one would fall into a trance and be open to any suggestion, command or trigger he gave that person.

He decided it was time to finally get laid, and he knew exactly who he wanted.