Prologue

Realm of death

Time: Non Existent

Death, one of the most powerful beings in the multiverse was heartbroken again. The Agony, Pain, the humiliation Death suffered cannot be expressed through words. A normal human may have become batshit insane by the events of last couple of eons.

The reason for such distress- The Mad Titan- Thanos.

Thanos has once again collected the infinity stones. he has once again won his sick game. It all began when Death chooses a mortal as her plaything.

Death in her countless years was bored of being alone and tired of living beings getting terrified of her. The last interesting thing was when Knull having a temper tantrum and killing celestials left, right and centre. It was good times for Death as she finally got her hands on celestial souls. Even she was happy as the celestials didn't have any respect for life and death. She had no Problem with their life creation, but resurrection was not something she likes besides, Celestials escaped the previous universe and their death. So, when knull started his crusade, Death took a front row seat and enjoyed his crusade. Alas! everything came to an end and the boring life continued for her.

Later, the next interesting thing was a titan-deviant hybrid Thanos. Death played him for fool and made him love her. Later when she was bored again, she made a deal with him to get rid of him. Death told him that only a mortal who became her equal in power can be her lover and thus Thanos began his crusade to become the supreme god. When Thanos began slaughtering planets and looking for infinity stones, Death didn't even mind him, but other cosmic beings did mind Thanos's crusade. One such being was The Phoenix, when Thanos came to kill half of the planet including an Avatar of Phoenix, she was very wrathful. Alas she couldn't directly interfere with Thanos so the Phoenix went to Living Tribunal to make Death pay for her games with Thanos. The Living tribunal judged Death's action wrongful and punished her by making Death living a mortal life without being aware of her immortal life in any one of the planet of her choosing. Additionally, he also made Death's words that when a mortal becomes her equal/Supreme God, they became lovers binding to Death. He also made Death to create a quest to become her avatar/equal in the planet she is choosing within 10000 years of her birth.

Death chose Earth and lived a mortal life. She had 3 sons who had magic. Later the 3 sons started a clan so powerful and terrifying that even centuries later the clan's name was a bogeyman for other purebloods, "The Peverell". Death's mortal life ended when one of her grandsons sacrificed her life for magical power never knowing the true identity of the mortal women. Ever since the ritual all Peverells were dealers in death and destruction and terrifying Lords of Magic. After couple of centuries Death decided to leave 3 items with the current Peverell brothers with a curse attached; The Deathly Hallows, the quest for becoming Death's Avatar/Equal. Death knew no one would master the 3 objects and then welcomes her with open arms. Additionally Thanos will never find the planet to unite the Hallows and becomes her equal. Death's belief held true for 5000 years until Harry Potter united the Deathly hallows and willingly died for others. In these 5000 years the deathly hallows became a myth among the multiverse. A chance to become an entity's equal. To become nigh, omnipresent, omniscient. Harry Potter, a descendant of 2 brothers became avatar of death returned to life not knowing the truth of things. Later Harry became the only Avatar of death and Death's lover after 20 years of peaceful life, then comeuppance came upon Death for her dealings with Thanos.

After Centuries of patience, planning, war and killing billions of people Thanos had achieved the impossible, something that even The Elders of the universe or elder gods had not attempted since the beginning of the universe, he had united the six Infinity Stones in Infinity gauntlet made through magical and technological URU and completed Death's challenge to become an equal- a Supreme God.

Upon reaching the Realm of Death, Thanos, now an omniscient being, understood Death's games and truth of his entire existence. Wrath unlike anything filled Thanos and he killed Harry in front of Death again and again by resurrecting him in many cruel ways. Even Death couldn't interfere since both Harry and Thanos are mortals, not yet cosmic beings. Death was truly worried whether she could defeat the infinity gauntlet wielding thanos even if she could interfere. Death who was connected to Harry could feel every second of torture he suffered under Mad titan's cruelty. Death could barely shield Harry's mind and soul from turning insane while dying again and again. Harry, being the avatar of death was powerful, but inexperienced in cosmic fights, he lost every time he tried to fight. Seeing the hope and never ending will to fight in the eyes of Harry, Thanos decided to play his own games. He used the Gauntlet to send the universe back to the day harry lost his parents and his first contact with Death and relive his entire life again and again. Every time Thanos unites the stone and remember previous loop meanwhile Death herself not affected by time reversal informs Harry of impending fight when he ascends to Avatar of death. Harry remembers previous lives when he enters Realm of death for the first time. In all the countless loops till now Harry has tried many different ways to win but everything leads to a painful end.

Many Loops later…

Death looked upon her innocent lover and partner after all these times of suffering and answers his question "No, Harry I cannot interfere. It's beyond me."

"Can you please send my memories back as of now in this loop? If you can do it, I may have a chance to kill Thanos for once and for all. Every time after I become the Avatar of Death, I couldn't increase my power level any more. No rituals or enhancement works anymore." Harry asked again.

"I can send memories and even souls back, but I can't do it for you as Thanos is using the Gauntlet for sending you back. I am really sorry Harry"

Harry looked death dejected, it was the last idea he had to escape from this hell. His eyes widened as he had an another insane idea. His "Death" is the primary Cosmic being of the concept of DEATH, therefore has the entire knowledge of multiverse and meddle in it, if required.

"Death, what of another avatar of deaths? What if you send another me from another multiverse to help me?" Harry exclaimed.

Death was intrigued by the idea, "Harry, while I can do it, there are no other universe in which I create true deathly hallows. The wand, the Cloak, and the Stone exists, but it's not created by me like this universe. Every other multiverse has a Death, but it's just different aspects of me. I only have you as my Avatar."

Harry pleaded to Death "It's not a problem, please send a powerful harry as my twin brother or one of my friends or anyone with the required knowledge. Please do it Death, we can't suffer anymore and even the world is stuck in this circle. I have one more insane idea Death. Countless number of times I have travelled this world for an advantage and help, but nothing is enough. Infinity stones cannot be found by me since Thanos wishes for me to not find it when he sends me back. Infinity stones only work in this universe. Let's change the universe when he sends me back again. Let's merge some new multiverses where powerful beings are there and even when Infinity Stones go back it will be updated to the new universe and I can find them."

Death was surprised. In her long-long existence, it was second time she was surprised. It is ironic since first surprise came from the success of Thanos in becoming a supreme God. Death wondered whether her shielding of Harry's mental faculties was a success or not. To merge universes is not something even a cosmic being such as herself could do without consequences. She has the power to do it, since she has omniscient presence in every multiverse.

Death said "Harry, in the next loops travel through multiverses and decide which ones to merge with the primary one. You can do by using America Chavez easily. Otherwise, the hard way is also there. I must talk to my elders about this."

Lady Death asked The Living Tribunal for permission of merging couple of universes. Tribunal was wroth with the insane idea and was about to punish her again when One Above All appeared.

"Enough with your punishments, Tribunal. It was your punishment that made Death create a path for a mortal to ascend to multiverse level." OAA said. " Death, you can do whatever it requires to deal with this Thanos situation, but the cosmic rule of non-interference should be followed. He is now in your level and it will be disastrous if he get bored with his current game and try to acquire more power from beings like Beyonder, or the Anti-Life Equation then he may even overcome me."

Both Death and Tribunal paled hearing that Thanos may come close to OAA.

Death said, " Ok. I will deal with it. I will merge the universes as recommended by my equal."

In the following loops, Harry travelled through various multiverses, where Thanos doesn't even exist and learned many secrets of various so called Superheroes. Harry was very impressed by two alien beings who may become the most powerful mortal in their universe. He even travelled to the universe from which Thanos originates the so called 'Marvelverse' and committed so many crimes to learn everything about various powers in it. The accumulation of such vast knowledge was unheard in the cosmos.

Many Loops Later…

Harry appeared for the first time before Death in this loop.

"Harry, Harry, So nice to see you. Finally, do you have a plan? Which universes to merge?" Death asked.

" Yes, I have decided my dear. Merge the Marvel, DC and Invincible to my own verse."

"Marvel and DC I can understand Harry, there methods to acquire powers in those verses, but why Invincible? Why do you need those war thirsty sociopathic washed out Kryptonians when you have the original?"

"It's precisely because of that I need that verse and of course to acquire the power of Viltrumite's adaptation. I need sociopathic warriors, after all Thanos has an Army of billions."

" Interesting… So you only need Viltumites for an Army? Harry, please be careful, DC has it's own powerful beings that may endanger your plans."

" Yes, but I need Mark Grayson too. So please make sure he exists. I will be careful of dangers my dear."

"Ok, I will merge the universes as requested when Thanos turns back time sent you without memories to the night of your parents death. The moment the killing curse touches you I will merge the universes past, present, future and uses the changes to insert your current mind and soul in your 1 year old self. I don't know when your body will adapt to the change, until then it will be very painful".

"Wait, wait, you said even the past will be merged? So you can change my own history and make me a mutant also ?

" Yes, I can merge the worlds history and make you a mutant, but the power I cannot guarantee. It's truly random. I can influence it of course, by making your mothers family a prominent mutant family."

Hearing this, there was a truly monstrous smile on Harry's face as plans after plans were made and discarded using advanced occulumency. Seeing the smile even Death itself get a chill down her spine, afterall knowledge is power and Harry has the entire history of the 3 multiverses and now manipulate it as he wishes before he starts his latest journey.

Prime verse

Oct 31st 1991

Godric's Hollow

Lord Voldemort sneered down at the dead body of Lily Potter. 'Foolish girl should have used my offer and stand aside. Poor Severus, he can choose some other redhead even though they may be pale in comparison to Lily, even I can see how attractive she is.'

Voldemort looks into the crib and saw a one year old looking at him. Voldemort felt like the green eyes were looking through him and suddenly he felt a minuscule presence behind him and turned, a Mage shield already beginning to form, but there was nothing there. Voldemort laughed to himself and turned to cast.

"Avada Kedavra"

Voldemort watched with a crazy grin as the pale green light of death travelled slowly toward the child and hit his forehead and

The Universe stood still for a second..

Authors Note: A crossover story that has been inspired by many other stories I have read. It's a muse that has been in my mind for many years. Updates will be sporadic because even though the idea has been in my mind for many years, there is no continuity for the scenes. Many situations for later has been imagined, but to write it in continuity it takes time and plan the timeline out.