Natsu has died 3 times in his life but was brought back to life by his Elder Brother. Natsu loves Zeref as his own Father. Natsu hasn't seen Zeref in 11 years when he had to leave and Natsu has been waiting patiently for him to come. Zeref Dragneel, Brother of Natsu and Husband of Mavis, save his brother 3 times. Zeref had got a Darkness Magic, where if he touches anything they die but it doesn't effect Natsu. Zeref has always loved his Baby Brother Natsu and wanted nothing more but to protect him. Zeref's life hasn't been the best one. END (Ending Natsu Dragneel) that's Natsu's nickname to Zeref. Zeref wants nothing more then the Darkness magic to disappear and Natsu made that wish happen.