You and Draco have been enemies since 4th year. The problem is that you were killed by Voldemort because you were considered a "threat" to his plans. Draco can see your ghost and he's the only one who can.

Last night was a fun night. You got to manipulate Draco into acting like a little puppet but you accidentally made him obsessed with you while you did that.

On the train ride to Hogwards Dream is talking with Pancy and Blaze. They bring up the topic of Layla and he takes control of the situation.

Draco: I can still hear their voice loom but they only exists in the dark of my room. Draco's thoughts 'I can't ignore you~ Do anything for you~ I do adore you~'