Chapter 1- First signs

What happens when all dragon slayers get their last feature of the dragon?
No-one is ready for what will come, not even the dragon slayers themselves...
What is going to happen to their "mates" when the dragon slayers get to them, will they be safe or will they be in danger???
Why is natsu and sting after lucy, who is her real mate?
Mostly contains-NaLu, StingLu
Mild- GaLe, MiraXus, RoWen, RoYu (rogue x yukino), CoKi (Cobra x Kinana).