A/N: Firstly I want to tell you guys that Juliet and Heine are actual people. I thought making them actual people would be nice. In the canon they were sentient swords but I thought that this will be nice I hope you don't mind.
Next is I want to send Axel and the girls to One Piece world because I only know about that world, that I have read from fanfics. I have not watched a single episode or read a single chapter of the novel or manga. So I don't have enough knowledge about that world to write a separate fanfic. I only know what happened in Alabasta Arc to Marine War arc.
I want to send Axel and the girls in a world where they can learn something so that they become strong. Not some weak ass world where they could easily crush anyone who they come to face. And I personally think that being able to see the future is truly op and all the abilities of Marines are also nice when mastered. Arnament Haki and Conqeror Haki is op too so I just hope that you guys understand what I am trying to say or do.
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After they came back Makarov and the rest of the guild was shocked too, it does not happen regularly that someone goes on a mission and finds someone's mother. When everyone including Makarov thought of it they found that it had happened before. Nobody knew how or where Axel found Ur, Ultear's mother, and Gray's master. According to Gray what everyone knew that she sacrificed herself to stop Deliora.
But now she was also brought back by Axel, Axel never told anyone how he brought her back except his future wives. Makarov had asked Axel once but seeing Axel being evasive he gave up. And now it was Erza's mother, though none of them knew what happened to Erza's mother including her so it was quite plausible that she might be alive somewhere. But when they heard how strong Irene was that shocked them because she could easily overpower even Makarov.
Axel decided to give the details of Irene's whereabouts to only Makarov. So he took Irene along with Erza to Makarov's office so that they can char privately.
Makarov: This is definitely shocking... though I am happy for you Erza.
Erza: I know Master, I was shocked too and I am currently very happy to get my mother back.
Irene: I also never imagined getting back to my daughter in this manner but it happened and now I am happy... very very happy.
Makarov: But I would very much like to know why you abandoned your daughter or left your daughter??
Axel: That is not important but Irene did it to save and protect Erza. I don't think that either Irene or Erza will give you details about this and neither am I.
Makarov: Fine... I have no problem with that. You guys trust each other so I will also trust you. So Axel what do you wanted to talk about.
Axel: Ohhh... I wanted to talk about Irene and her lackeys joining this guild.
Irene: Don't call them my lackeys Axel...!!!
Axel: Fine... sorry my bad. Juliet and Heine would also like to join the guild.
Makarov: But why do you want to tell me this privately??
Axel: Because...
But before Axel could finish Irene decided to talk herself.
Irene: I betrayed my country along with Juliet and Heine to come here.
Makarov was completely shocked to hear that, he knew that Fiore was not in friendly terms with nearby countries so if someone strong like Irene has decided to leave their country and it could result in trouble for them on a later date. Though it was not like that he would deny her and throw her out.
Makarov: I hope you don't mind me asking which country.
Irene: I am from Alvarez Empire and I was one of the Spriggan Twelve.
Makarov turned completely pale, now he knew why Irene was so strong. She was even stronger than himself. Obviously he didn't know about their Emperor or he would piss his pants. But he knew that they were not in friendly terms with Alvarez Empire and how strong Spriggan Twelve were. Only he or Gildarts could even face one of the Spriggan Twelve and seeing Irene in front of him made his belief more solid.
Makarov started to think in his mind seriously and decided to go with the flow but suddenly he remembered a small detail. It was clear to Makarov that Irene was stronger than Makarov and Axel have defeated her with ease which meant Axel was way more stronger than he has imagined. He had thought Axel was Gildart's equal but now it was clear for him that Axel was way more stronger than Gildarts too.
Makarov: I am completely fine with you joining the guild. But please don't break our trust.
Irene: I would never do that.
Makarov: Oh... by the way Axel there are two new members of our guild so don't go on killing them.
Axel: Let me guess Gray's Yandere Stalker and that Iron eater??
Erza and Irene started laughing because Axel had hit the nail correctly. Juvia was exactly a Yandere Stalker. Iron eater meant the Iron Dragon Slayer of Phantom Lords. Makarov's face became completely blank but it was because he was trying to stop himself from laughing. After a few moments, he became normal and coughed in his hands.
Makarov: Yes... Juvia Lockser and Gajeel Redfox.
Axel: As long as they don't create any problems for me, my girls, or our guild I will let them be.
Erza: Same with me.
Makarov: I guess that takes care of it... Axel ask Mira to give Irene and the girls their guild marks and Erza you tell me what exactly happened on your trip.
Erza: Yes... Master.
Axel didn't reply Makarov but just nodded his head and left the room with Irene. Axel then took Irene, Juliet, and Heine to Mira to get them their guild marks. After the guild marks were done Axel went to seat with Ur, Ultear, and Cana. Cana was drinking booze directly from a barrel which was quite a usual sight.
Ur: So they didn't have a problem I assume?
Axel: Yes... they didn't have any problem. Cana last time I didn't have the time to ask you this.
Cana stopped drinking from the barrel and looked at Axel.
Axel: Would you like to move in with me??
A huge smile appeared on Cana's face and she put down the barrel on the table and jumped on Axel and started to suffocate with her impressive chest. It irritated Irene but she didn't mind because they were still not in a relationship. Ur and Ultear were completely fine with that. After a few moments, she let go Axel and picked up the barrel and chugged it down in one go. After that, she grabbed Ur and Ultear's hands and ran out with them.
Irene: What just happened??
Axel: She took them so they could help her with moving in.
Irene: Oh... your girlfriends don't seem to be jealous of each other.
Axel: At first they were... but now they have no problem with each other since they have become familiar. And I don't any of them any kind of special treatment so that helps too.
Irene: Good choice.
Irene and Axel kept making small conversations when Juliet and Heine got bored and went to talk with Lucy. Axel then remembered that he haven't seen Meredy in the guild. So he went and asked Mira who checked the logs and found that she went on a mission with Alzack and Bisca. Axel went back and sat with Irene.
After some time Erza came back downstairs then all of them exited the guild and went to Axel's house. Axel's house was big enough to accommodate all of them. Axel didn't go home but he went towards the real estate office because he wanted his new house on the beach. When Axel could no longer see Erza, Irene, and the girls he started to think aloud about the next events.
Axel: I don't want to fight that weakling Laxus... I will let Erza or Natsu fight him...
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A/N: Another thing is that Natsu is not the main character of this fanfic, that is why I am writing this. So if Natsu becomes weak due to lack of challenge honestly I don't care... fanfic is something authors write what they imagine what a world could have been if the MC had these kinds of powers. Fanfic is not meant to be followed by the canon plot to support how the original MC gets stronger....