Hai! What if Natsu went on a mission after the Edolas arc, and got captured by Grimiore Heart, being used as an experiment, but slowly turning dark? That might have not made any sense. Also, there will be a two month interval in-between the Edolas arc and the Tenrou arc. Natsu will be OP. Ultear and Jellal will join Fairy Tail. This is a Natsu harem fic. There will be lemons. Enjoy!
Grimiore Heart HQ-3rd Person
"Master Hades, we have given subject #7014 all types of slaying magic, requip, molding magic and unlocked his ancestral magic." a unnamed mage said to a tall man with white hair, an eyepatch and a wearing dark clothing.
"Good. Ultear, what level of Origin Release does he have?" the master of the dark guild asked a slim, woman with a curvy figure wearing a purple kimono.
"The Seventh Release, sir." the woman replied. She was excited that there would be a chance to destroy the legal guilds in one fell swoop. She turned around, hearing footsteps coming from the hallway.
"Master Hades, subject #7014 has awakened." the messenger said, reporting the news he received.
"Excellent. Ultear, would you like to try and persuade him?" the guild master asked the time mage.
"Yes, I shall." she replied, and started to walk towards the cell.
Cell #7014-Nastu
Natsu woke up in chains. He remembered finishing a mission alone because Lucy was with Erza, Gray and Wendy. He remembered that he was defeated by two mages, one with brown hair and a muscular figure, the other with long blond hair with a lean yet muscular figure. He looked around him, noting that the chains were attached to cuffs on his tried to pull on them. That failed, so he tried to burn them with his magic.
"No, you shouldn't do that." a voice said.
Natsu raised his head. A door materialized out of nowhere and a woman came out. She had dark purple hair, and a revealing purple kimono. She also smelled familiar...
"Your the old man from the demon island!" he said. The woman's left eye twitched, and she expressed an aura of anger.
"I'm not an old man! Anyways, you're here in the Grimiore Heart headquarters." she said to the dragon slayer.
"Wait! That's a dark guild! What do you want with me?! Why can't I use my magic!?" the dragon slayer yelled, now aware of the situation.
"Calm down, Zancrow and Azuma found you in a forest, so they took you back here. Now, you'll understand why you're here shortly, and the cuffs and the chains negate magic." the woman replied calmly.
"Why'd you bring me here?! Where's Lucy and the others?!" Natsu retaliated, in a fit of panic and rage.
"You're so called friends aren't here. By the way, my name's Ultear." the now newly named Ultear said.
"What do you mean 'so called friends'? asked a confused Natsu.
"Oh, you don't know? Your friends abandoned you." Ultear said emotionlessly.
"They would never do that!" yelled an infuriated Natsu.
"Hm, could your fiends offer you to find your foster father?" Ultear questioned.
"What?" asked a calmer Natsu. He heard her say that his friends abandoned him, and that annoyed him to no end, but to find his father? He had to know more.
"Alright, if you want the truth, follow me." After Ultear said this, the chains were detached from the cuffs, allowing him to stand up. He followed the time mage to the room where master Hades was. They stopped in front of the doors to the room.
"Ultear here, along with Natsu Dragneel." the time mage said, and the doors opened.
They walked in, and Natsu saw a tall man with white hair and dark clothing. The woman walked up to him, so Natsu followed.
"Ah, there they are. If you could follow me." the man said. He led the two of them to a table where they sat down.
3rd Person
"The old man said that you had some info on Igneel." the dragon slayer said to the dark mage.
"The old man?" Hades asked, confused.
"He means me, and I'm not an old man you dolt!" Ultear said while glaring angrily at the dragon slayer. Hades chuckled.
"Yes, we here in the guild of Grimiore Heart want to go to the World of Great Magic, where only mages, and magical creatures can survive. This world is our goal, and all magic, caster, holder and lost will be complete, with no drawbacks. We have a theory that dragons are able to go to that world as they are legendary creatures, with outstanding magic, so your foster father Igneel could be there." the guild master explained.
"Alright, how do we get there?" questioned Natsu, eager to find his father.
"You cannot just go to the World of Great Magic. However, you should hear what Ultear has to say." Hades said, allowing Ultear to speak.
"Like I said before, your friends abandoned you." Ultear said.
"That's a lie!" was the response she got.
"Really? Then why haven't they tried to look for you yet? Here." she said, taking out a lacrima sphere. Natsu stared at it. Images appeared. Lucy, Happy, Wendy, Gray and Erza were at the guild all happily talking each other. Though everything seemed normal, the brawls, the drinking, the laughter, it seemed like they didn't care about him anymore. He felt alone. He just stared at the images of his guild, and his emotions got the best of him. All around the Girmiore Heart HQ, you could feel enormous magical power coming from the center. Ultear and even Hades were cowering under the pressure of his power. The magic suppression cuffs were still on, so this was only part of the power he held.
"HOW DARE THEY? THEY JUST FORGOT ME LIKE I'M SOME SORT OF BUG! HOW COULD THEY DO THIS TO ME?!" he yelled, and the pressure increased even further.
Ultear felt... hot. The magic power she was feeling was turning her on. She wanted to be pounded by the hunk of man in front of her. She wanted to grovel at the feet of the god that was Natsu Dragneel. She wanted to be taken and claimed by the powerful dragon, she wanted to get pounded hard and fast, to be reached so deep inside of her that she would stay in that position forever. However she stood up, and tried to calm him down. She knew that if he released any more power, the HQ would be destroyed.
"It's okay, you can get your revenge, join us." she said. She wanted him to join because he was powerful, and she felt sorry for him. The other reason was that she needed to be his. Kain was fat, Zancrow is a bit insane, Rustyrose was to girly, and Caprico was strange. The only one she could stand was Azuma, but Natsu was more powerful and sexy.
Ultear walked up to Natsu and hugged him, her large breasts pushing into his muscled body. The pressure lessened a bit, and it stopped completely. Natsu hugged her back, and she moaned loudly as she felt her boobs come into contact with her lord's abs.
"Ahem, what is your answer?" They were interrupted by Hades, who was inwardly pleased that he got Ultear to persuade him.
"Yes. I'll join Grimiore Heart"