Year 1516
Calm Belt- first half of grand line
In the depths of a hell called impel down, also known as worlds worst prison, divided in six floors, the more deep the floor, the more vicious criminals it held.
Level six of impel down also known as eternal hell, all the criminals here are with bounties of at least 100 million berries, here also imprisoned a marine or it's better to say ex-marine. His face can enchant anyone, men will die with jealousy and women might strip themselves just to get his attention. However this is not most important fact about him, two years his strength had already reached the level of admiral candidate which earned him respect of several marines, women in particular were obsessed with him, his name is Castle Fenix.
Fenix was an orphan adopted by a marine, who also became his mother, name Amanda a rear admiral under Admiral Aokiji's command. Following her Fenix also became marine and shown other-worldly talent in combat, he learned six-styles along with life return and six Kong gun, within a month, within 2 months he mastered haki to a good extent, that put several vice-admirals in shame, he reached the rank of real admiral by the age of 16, which is the same rank as his foster mother, he never stopped his training later he ate a devil fruit a mythical zoan at that, which increased his fame and importance in marines far more than anything, he was considered as potential future admiral, most outstanding talent in history of marines, he cleaned up first half of grand line in 2 months single handedly without needing a warship, let alone a fleet. He always kept an eye on pirate list, visited intelligence department frequently, when he get the information and current location of the pirates, he'll fly over to the location or next predicted location, he became nightmare for pirates, he hunted several pirates beyond hundred million bounty and also a few pirates who didn't even started journey. This led to his rapid promotion and gained admiration from several marines, but everything, comes to end two years ago his foster mother assigned to escort a celestial dragon, under a vice admiral Yamakaji, during the escort mission on Sabody archipelago she tried to save an innocent woman whom celestial dragon demanded to be enslaved as his 23rd wife but during this she offended the celestial dragon, who was about to demand to torture but Vice admiral Yamakaji being from Aokiji's faction beheaded Amanda to save her from torture of celestial dragon, when this news reached Fenix's ears he decisively flew over towards Sabody to slaughter the celestial pig, but World government had intercepted it at ordered Sengoku and Kizaru and vice admiral Gion to arrest him, Fenix fought for whole day before ending up completely battered and defeated, he also awakened Conqueror's haki in process. Later, when he was imprisoned in impel down he started practicing also using the cheat he got to after transmigration,
[ talent absorption system: You'll be able to gain the talents of other individual, the more you'll be in contact the faster, the talent will be gained]
So in impel down level 6 where all the dangerous criminals are imprisoned, when he arrived in this world first time he got a talent for free and decided to get indestructible body, a natural destroyer body higher level than big mom's steel balloon physique, later when he met Zephyr as instructor he taken his template and spend most of the time in training, later after a contest he was offered to get any reward he wished, weather it is a sword, an special equipment, a devil fruit or anything in line, he asked most simple thing which impressed Zephyr and Garp but also gave headache to them. He asked to increase his training intensity and resources and have the instructor to guide him for 15 hours of the day, in 8 months he was successful at gaining Garp and Zephyr's talent and his haki's quality became super strong as both of them have strongest haki in marines, later he spent his time sparing with Aokiji and Kizaru and his haki and devil fruit mastery increased, yes he'll not get other devil fruit powers but mastery over his own devil fruit will be increased,
Fenix: System, show me my status
[Name : Castle Fenix
Age: 18 years
Physique: Indestructible Vajra Physique
Devil fruit : Human-Human fruit, model : Devil King Lucifer
Armament Haki: advanced (i.e Low, medium, high, advanced, peak )
Observation Haki: advanced
Conqueror's Haki : High
Devil fruit mastery: Peak (awakened at high)
Talents: Swordsmen ship, six styles, conqueror's path, steel bones, insurmountable haki, sharp strategist, ….]
He got several talents from likes of Dougles bullet, Observation haki from Patric Redfield, giant strength from Sanjuan wolf and few other skills and devil fruit mastery which had reached the peak from other it took 2 years to prepare.
Prisoner1: oh see who is here, the marine hero, what does vice admiral Garp have to do in level 6, don't tell me, you are here to free that marine brat.
After hearing so Fenix saw an old marine clad in vice admiral uniform with unique design, he has a burly figure withered hairs and beard, he is a legendry figure "marine hero Garp", who almost cornered Roger several times. This man walks directly in front of Fenix's cell ignoring all the other prisoners yapping, as he was assigned special cell with all of his limbs bind by sea stone cuffs, Fenix's eyes moved up and looked at the old man
Fenix: Well, if it's not the Marine hero, why someone of your stature come to meet a lowly person like me.
Garp looked at the young man with pain in his eyes, the young man in front of him was someone whom he thought as future of marines, a talent he has never seen but fate was cruel to him, in his opinion a few celestial swine does not worth anything in front of this young man.
Most promising marine got locked in Impel down, it sounds like marine had become a joke
Shiryu: Oh, it's you old man, are you here to see your old disciple,
Garp: Shiryu, I heard that you killed a few prisoners to satiate your bloodlust and got imprisoned, it seems like it was not false, well I'm not here for you anyways
Shiryu: Are you saying that brat is going to free
This statement gathered several gazes but
Fenix: something as good as that do not exist, this old man here is just to have a chat here, right vice admiral Garp.
Garp heart clenched again and he sighed helplessly
Garp: sigh! Brat I also feel pity for you to end like this
Fenix: well, I know you are not here to just say those words old man, so why are you here anyways.
Garp: One of my grandsons had started his journey as pirate, I always gave them your example but they are dead set on becoming pirate.
Other prisoners cannot hear Garp otherwise he'll surely be mocked by them
Fenix: oh, so Ace, has started well he has guts with grand ambition just like his father
Garp: I hoped he'll not take his father's path, now my own grandson continuously ranting about becoming pirate
Fenix: I don't know if he'll survive after all, he doesn't have that much of a brain.
Garp: Luffy, yes, he's a fool but he's kind child, I hoped him to become a marine but I don't think it'll be possible
Fenix: leave it old man, if he became a marine, he'll be just a trouble, also he doesn't know how to read and write how are you expecting him to write reports.
Garp: I don't know how to answer it.
After a few moments of silence
Fenix: You know I don't think marines are justice anymore, they more seem like pets of celestial dragons, that should be the perfect name for them.
Garp heart clenched by hearing this for the organization, if it were anyone else, he would have he would have rebutted but he knows in front of Fenix he doesn't have the right to do so.
Fenix: Hey old man, do me a favor
Garp raised his gaze and looked at him and Fenix said in calm tone
Fenix: tell those who participated in my capture, if I ever got out of this damm prison, I'll hunt each and every one of them, and those pigs who are their masters will be the prey I'll relish most.
Garp shocked up and stood up grabbed his coller
Garp: Have you gone insane, it was not their fault
Fenix: Oh, tell me if you were asked to take a child life by those celestial dragons, will you say that it is not your fault
Garp: I'll reject the wish of those scum; they can't do much to me anyways.
Fenix: What would you have done if they were, if they asked to kill me?
Garp: Of course I would have rejected.
Fenix: Sengoku aside Gion and others could have rejected, but no for their so called-marine duty of worshipping dicks of celestial dragon, they accepted
Garp: she still regrets taking mission.
Fenix: I don't think so, she is admiral candidate even during that time, right? She had enough influence that she could avoid the request like you, but she accepted and you know what if she were asked to serve that celestial swine in bed, she'll gladly spread her legs for sake of marine-duty.
Garp heard enough and can't take anymore, punched him and grabbed his collar
Garp: Don't you dare to spout any non-sense you imbecile.
Fenix: as I said I don't care, now if you please just do this last favor for me and deliver my message to them, they wish I'll not be free from here because one I did, I'll make them regret that they born in the era where I existed.
Garp clenched his collar but did nothing else he knew that Fenix lost trust in marines he lost his way, who'll not if they were betrayed by the very organization. Garp relaxed his grip and turned around
'it's better if this monster is not unleashed because, young marines will die at his hand'
Prisoner1: oh, you see that how mighty have fallen from grace, marine hero trying to curry up a fallen soldier
All the prisoners who have nothing to do started laughing at this, there are few who did not after all it doesn't interest them. Fenix is already planning to escape in next few days after all he have nothing to do here anymore.