Natsu had a 20 minute gap between him and the guild. If anyone were to go after him, they'd be too late even if Erza used all her magic on a vehicle.
When he had slipped away from the guild, Natsu had made his way to a stable and rented a riding animal. When the owner told Natsu that the creature was quick, they weren't lying. The dragon slayer promised to bring the animal back, but deep down he knew it wouldn't be him bringing the creature back to it's owner. Eventually Lucy would come after him. If not Lucy, then Erza or Gray.
"I'm sorry Luce..," he muttered as the animal and him made their way back to the area Zeref was located. Once again, Natsu had left Lucy without a word of warning directly to her. But this time he wouldn't be coming back, he knew that and he was prepared to sacrifice himself for the survival of his friends.
Lucy was going to be devastated, he knew that. After what she told him what happened to her when he left the first time, he knew it would be hard for her to forgive him.
Scenery passed by while the only sound was the beast's breath and movement. It was almost peaceful if it weren't for the guilt overwhelming Natsu.
How would Happy react? He would have Lucy but together, who knew how they would be. Emotion twisted his stomach, causing him to feel rather ill.
Soon. Soon he would be beat Zeref. He could feel it and shoving any regrets to the back of his mind was required. Natsu forced himself to only think of defeating Zeref for the future of his guild mates.
Natsu banned himself from thinking of the upsetting emotions. He had to think of the future. A future without him. A future he wouldn't be able to spend with Happy or Lucy.
"I'm sorry Lucy..," he paused, feeling Zeref's power grow closer.
" I'm sorry Happy..," the animal stopped, forcing Natsu go climb off and run.
"You were a great friend, Happy ," Zeref was in view.
"I love you,Lucy..,"