{Author Note: I'm removing Alucard from Mars Peerage. As much as I would love for the badass crimson fucker to cause mayhem but I doubt I'd be able to....word him correctly so I'm not going to take the chance. So Rossweisse will take his place in his peerage.}
Mars opened up a universal portal to the Fairy Tail Universe but then waived and said "Bye, you cocky overgrown lizard." Which caused a anime tick mark to appear on Great Red as Mars and Grayfia stepped through the portal.
When the portal closed Great Red yelled "Good Riddance that brat is gone."
Mars and Grayfia looked around as they found themselves in the Mountains. Grayfia looked her lover and asked "Why are we in the Mountains or more specifically a cave?"
He looked at her kneeled then touched the cave floor as his hand glowed green abit as he looked through time using Akatoshs power. He got up and said "the year is X500" 'and 284 years before cannon starts.' He and Grayfia left the Cave only to find that was night out and that it was night and snowing so they went back to the cave. They could have ventured out of the cave into the cold night Mars had a feeling that he would find something interesting in this cave.
So they both went deep into the cave, once the got deep enough they find a large blue scaled dragon sleeping. It raised its head and asked "What do you want, human?" Or at least that's what the dragon thought the two people that was in front of him once he sniffed at them he immediately knew that they werent human. That's when he said "Human? No, none of you smell like humans do. So then what are you?" He had an idea of what they were based on his fights with demons from the book of Zeref but this dragon just wanted to be sure.
Mars looked at the dragon and said "I am Mars Gremory and the woman next to me is Grayfia Lucifage, and we are Pure blooded devils. No we are not made from Zeref. We are Devils from another world." Grayfia nodded at his words.
The blue scaled dragon then said "You're not made from Zeref? Good. I suppose I should introduce myself then I am Thunder, The Lightning Dragon King."
He looked at Thunder and said "I have a proposition, Thunder. I would like you to train me in Dragon Slaying Magic. In exchange when I Leave this world I will take you with me to my world. A world without Acnologia. A world with Dragon Gods and Dragon Kings and hundreds if not thousands of dragons that still exist, though in the Underworld but still they exist. What do you say?"
Thunder pondered a bit, a world without acnologia would be great he thought and nodded his head and said"I accept." The first thing Thunder did was make a Lightning Dragon Seed and pushed it into his chest.
He wanted dragon slaying magic to better protect the devils, but he miscalculated something. He had no idea just how painful it was going to be because he, a pure blood Devil was going to be changed due the dragon seed. The moment the dragon seed entered his body he screamed in pain. Grayfia was worried sick about him so she knealt down next him and placed his head in her lap as he writhed in pain. In his mind however was a different story, he was asking venus if she could create something that could separate the two different type of blood. So she created a blood tree 1 type of blood per branch, but something unexpected happened as soon as the blood tree appeared in his soul there was a third branch occupied. So he asked Venus 'What's the third Branch?'
Which she responded saying "Apparently when you Reincarnated you carried over your blood from your previous life but it was dormant. Now with the Blood tree your God abilities from your previous life has been boosted now."
'Huh. Is that so.' was all that he said in his mind as he stopped being in pain he looked at his changes and noticed that he now had fangs like what natsu had from the anime. He looked up Grayfia only to now realize that his head was on her lap. So he took Grayfias hand and kissed it before saying "Thank you Grayfia, now can you tell if I'm a Pure blood devil still?" He knew that the answer would be yes but he just wanted to be sure. Now the blood tree the dragon slayer magic curse will no longer affect him in the future.
She looked down at him smiling and said "Yes, I can. Though I am embarrassed to say but with fangs you look more menacing now. Now that I notice it, you're starting to look more and more like your father instead of Sirzechs as you get older."
He looks surprised at this and says "You sure? I've always wanted to look less like Sirzechs and more like father. Oh before I forget." He walked over Thunder and placed his hand on his snout and poured his demonic energy into the dragon king as a message popped up.
[Thunder, Lightning Dragon King has been added as your familiar. Familiar menu Updated.]
Thunder, now feeling something strange happen to him says "What is this that I feel?"
He looks at Thunder and says "you are now my familiar. What you feel is pure familiar contract, which you can destroy if you deem me unworthy at any time."
Thunder looks up at him and says "Alright then. I think we should start your training now and it will be the most intense training you've had."
He nodded at this and soon started his training the next day. Over the course of 190 years he trained with Thunder. When the year was x691 he slipped out one night and brought his devil wings which were now 5 pairs of bat-like wings since his promotion to Satan-class Devil after the Civil War, he flew at max speed and headed for Magnolia in Fiore to join Fairy Tail. When he reached Magnolia he brought in his wings and head towards the guild hall. When he entered the guild he looked around the place as his entrance brought the members of Fairy Tail to face him. This caused the founder of fairy tail to approach him.
Mavis, being who she is was the first to speak up. She looked at him and says "Hi I'm Mavis Vermillion. Master of Fairy Tail. Are you wanting to join?" Her magic was sensing him she felt awed and scared at the same time. She was scared because she senses something a different type of power in him, a type of power that could only be described by one word....demonic.
Mars looked at Yuri, Warrod, Pricht, and finally down at Mavis and says "I am Mars Gremory and yes I'd like to join Fairy Tail. I am the Lightning Dragon Slayer and a pure blooded Devil. Before you ask no I'm not one of those filthy fakes that were created by some mage named Zeref." Which caused them to sigh in relief, but when they found out that he was a devil they were a bit angry but when he said that he wasn't one Zerefs creations it brought relief over the group.
Yuri spoke up saying "Are you a threat?" Yuri had said something that was on there minds but were unsure how he respond so they didn't.
Mars did not look fazed by this question and responded "No. Well to Mavis Curse yes."
Mavis knew what he was talking about, she looked at him and asked "Can you remove it? I dont like it. It takes life away."
Mars smirked at this and said "Of course I can. Removing curses is easy for a devil of my power." He approached Mavis and touched her forward as he poured his demonic energy into her body which ended up purging the curse very quickly. He withdraw his finger and stepped back a bit, but was soon hugged by Mavis as Ankserhams God Curse was no longer present in her body. He got his guild mark and told themthat he'd be back in 5 years. He dropped a chest full of Jewel one the guild floor from his inventory that he got one time as a loot drop from the dragon dungeon I.D. at one time and left the guild hall.