Soul Bonded (слэш)

When Fairy Tail gets an urgent request from a temple in Bosco, they have no choice but to go. In order to seal an ancient demon, two opposing forces must be used. Natsu and Gray's magic becomes more crucial than ever, but there's a catch. The two mages must become soul bonded. Torn between saving lives and giving their life to someone they hate, the boys have big decisions to make. Gratsu Yaoi, rating will go up later.