Atem's first steps on earth were in Egypt, many many years ago. Born to the Pharaoh Aknamkanon and his wife Samira, Egypt's chosen son was welcomed by all. A few years before his birth, his father's younger twin brother, Akhenaden, led a siege on the village of Kul Elna. Killing 99 residents in a blood ritual, he created the Sennen items. The only child to escape the bloodshed that night was Akefia Bakura who would later come back to threaten Atem's reign.
When Atem's father found out how the items were made, in his grief and repentance he took his own life, praying to the Gods to spare his son from his mistakes. Atem was hoisted to the throne early because of these actions, unsure and unsteady, but still willing to try. However, it did not take long for Akefia to make his reprise, having made a pact with Zorc Necrophades, he comes after Atem. His blame is placed on the entire royal family, and wishes nothing but for their deaths. In trying to collect the Sennen Items created, he finally calls Zorc to the human realm. Atem battles the monster with all of his strength, but cannot win out in the end. Doing the only thing he can think of, he seals Zorc into the Sennen Ring, and using the last bit of his own power, sentences his own soul to the same fate. He decides in his last few breaths that his name will become the keystone for releasing Zorc; so it is erased from every scroll and from history forever.
His soul then split, the part locked in the puzzle wiped of any memories whatsoever, making sure that his name was to never be released. However another piece came to rest in his tomb, watching over the lands and waiting for the day when someone would solve the trials of his resting place to take the puzzle to where destiny decided it should be. The man who did just this, and subsequently was saved by Atem's soul, was Sugoroku Mutou.
Atem’s puzzle took Yuugi nearly seven years to complete, being extremely difficult. Yuugi’s one wish on the puzzle was to grant him friends. Though when Atem was first released he was a very vengeful spirit, not knowing anything about who he was or where he came from; his only mission to protect his, now, other half. When a student (Seto Kaiba) kidnapped Yuugi’s grandfather over an exclusive card, Yuugi rushed to his aid and Atem stepped forward to duel him.
His victory over Seto got him noticed by one Pegasus Crawford, the creator of Duel Monsters. He sent a tape to Yuugi’s home, though it was really a trap; when Atem failed to beat him in a duel within the time limit, Pegasus took Yuugi’s grandfather’s soul and gave them no choice but to participate in his tournament to get it back. The battles there were tough on their own, Atem meeting new faces and challenges; though one of his biggest was against, once again, Seto Kaiba. Seto’s brother had been kidnapped and the brunet was after victory. The only way he’d been told he’d get Mokuba back was by dueling Yuugi.
In this duel, Atem had the upper hand; however, Seto being determined to win threatened suicide. Atem weighed his choices for a moment before deciding that he could not lose- ever. He called an attack which Yuugi immediately pulled back from; a gap was formed between the two partners, Yuugi afraid of the spirit, and Atem sorely upset over his rash decision. This was only resolved through a long talk and their friends showing faith in both of them.
The last duel of the tournament was particularly stressful, Pegasus using his own Sennen item against the duo to cheat and read their minds. They decided to split up, each dueling on their own; it was then that Pegasus instated a Shadow Game, and Yuugi, being too weak to stand against such forces, quickly perished. This shocked Atem’s entire being, thinking he’d lost his partner. He vowed vengeance on Pegasus, finally beating him and helping Yuugi stand strong once more. The two became closer than ever after that moment.
After the defeat of Pegasus, a young boy by the name of Otogi was extremely upset; thinking Yuugi had ruined his only chance at releasing his game. He threatened Yuugi’s grandfather’s shop by opening his own game shop. To this, their best friend Jonouchi stepped in to try and help, but quickly lost against Otogi. Once more Atem accepted the challenge; not knowing the game placed in front of him, but going forward anyway, determined to help both his friend and Yuugi’s grandfather. It was here that he proved his tact and wit, his ability to integrate into any game placed in front of him. He beat Otogi at his own game, and they soon became friends afterwards.
Soon after that, a new evil targeted Yuugi and the Pharaoh; stealing the puzzle away from Yuugi as the boy was walking to school. Though the man that challenged him to that duel ran away, he smashed the puzzle and set the warehouse on fire accidentally. Yuugi fought to get his spirit out safe and sound, but to no avail. It was only when his friends showed up that he was able to get out alive. Atem became scared that he would only hurt Yuugi by sharing his destiny with him, feeling guilty for what had happened. Yuugi quickly reassured his partner that they were in this together.
It was after that that Yuugi set Atem up on a mock-date with his friend, Anzu, believing that getting out and seeing the world would help the spirit. Though Atem was completely distant the entire day, not finding anything of interest except shopping for cards. His mind was on other things, constantly contemplating who he was and what his destiny would reveal. It was only then that the two were led to the Egyptian museum, where a woman named Ishizu came to greet the Pharaoh welcome.
She started to explain some things about his destiny, and it was there that he realized he was a Pharaoh in ancient Egypt many years ago. Though this information didn’t truly shock him, he recounted that he knew he’d always been somewhat aware, if not of his lineage than his fate. Ishizu told him to enter Seto’s newest tournament, because only by doing so would he be able to get the items he needed to face his destiny once more.
That night, he watched over Yuugi, having a deep conversation with the other. It was explained that Yuugi didn’t want the Pharaoh to feel alone, even going as far as to exclaim that if Atem could never regain his memories, he would share his own. This warmed Atem, making him realize their bond was stronger than ever, and that he would never be alone. It was then that he knew his destiny was not far out of reach, and one day he would be able to face it; so long as he had his friends to rely on.
While they he dueled his way to the top, this time encountering new faces and perils, he continually came into contact with a man named Malik. Malik was after him, having cursed the Pharaoh for handing his family such a terrible fate. They were tomb keepers, destined to watch over the Pharaoh until his return. Atem wasn’t sure what to make of that at first, but the more Malik threatened to hurt his friends and acted out against him, the more his anger rose.
During a duel with one of Malik’s puppets and gets locked into a very desperate situation. Facing down a God card and an almost unbeatable strategy, he falls to his knees feeling utterly trapped and helpless. It was then that Seto appeared, glaring him down, declaring that if he were to give up then, he was not worthy as an opponent. They exchanged a few words, one particular set that made Atem realize that the Gods were not unbeatable. After he finished off the puppet, he went off with Seto to go save his friends.
They were stopped by another set of minions, trapping the two into a double battle. This battle was rather precarious, staged on the top of a building; whoever should lose would plummet to their death below. Seto and Atem didn’t work well together at first, which irked Atem- he saw no reason to be so distant when their very lives depended on battle. The brunet shirked him and continued to do as he pleased. Though Atem did wear him down, appealing to his common sense, and Seto went as far as sacrificing his prized monster to help Atem out of a bind.
Once the successfully moved from that duel, they flew to where Yuugi’s friends were being held captive. Jonouchi and Anzu had been taken under mind control by Malik, and Yuugi was forced to duel his friend. Though Atem tried to step into this, Yuugi warned him off, saying that he had to face this alone. During this duel, Atem became very wary of his partner’s choice, though he trusted the younger- even when Yuugi went as far as to hand the puzzle over to Jonouchi.
This duel, of course, ended in success; and the group headed off to face down the finals of the tournament. The first battle of which happened to be Atem taking on the spirit of the Sennen Ring. Bakura had a strategy to defeat the Pharaoh, though Atem outsmarted him and was able to summon his God card. Bakura switched with his host, attempting to appeal to Atem’s softer side in not wanting to hurt his friends. Again he was faced with the aspect of losing everything in front of him; straining to figure out what was right and wrong.
Luckily, Bakura took over for his host, taking the brunt of the attack in the end. After that, Jonouchi took his turn to duel, disastrous at best, and difficult for Atem to watch. After which Malik was finally revealed to the group, a much darker and insane evil than any of them could have ever imagined. Mai Kujaku went next, though her duel was rather miserable. In the end she got herself trapped, facing down one of the Gods, and about to be killed. Atem stepped into the duel, using himself as a physical shield to take the brunt of the attack- in no way wanting any of his friends to become harmed.
After the next duel between Seto and Ishizu, which ended in a loss for the woman, she handed over her Sennen Item to the Pharaoh, saying it no longer would work for her and that it belonged in his hands. She then asked him to save her brother, to which he sounded a resounding affirmative. Soon following those events, the ship was hijacked by an unknown presence, though later revealed to be the Big 5 headed by Noah Kaiba. They declared war on the young duelists, separating them and dueling them for control of their bodies.
The entire time, Atem worried about his friends, particularly the weaker of the bunch. He knew they didn’t stand a chance on their own and that fueled his anger and passion to break free from this world. Noah faced down Kaiba, nearly losing and deciding on freezing him. This enraged Atem and the spirit stepped in Seto’s place to finish the duel with a meager 100 life points. Though he was furious with the younger boy for acting so maliciously, and intent on teaching him a lesson. Though for a few moments he panicked, nearly losing, he never gave up and won out against the younger child.
In the end of it all, Kaiba faced down his father and crashed the virtual world and the tournament was slated to continue. The four left participated in a mock duel to see who would go first and against whom. Jonouchi was targeted by Malik and Seto simultaneously. Atem tried to help the best that he could, not wanting his friend to get hurt or go up against either opponent but not having a choice in the matter.
The order was decided, Malik VS. Jonouchi and Atem VS. Seto. The first duel was rather brutal, Atem having a tough time watching; ending in Jonouchi’s close demise. After losing his friend Atem panicked, realizing that his friends were getting hurt one by one because of him. Yuugi tried to console the spirit, but nothing worked; the depression deep-set. It was only by a reminder of Jonouchi’s spirit that Atem bucked up, heading out to face Seto.
That duel was magnificent, having the Gods face against themselves which ended in the world shaking, people on the edge of their seats. Through it all insults and remarks were thrown from both sides of the field, but Atem came out victorious as always; having something to prove, his friends to save, and a destiny to figure out. Losing was never an option. He then faced off against Malik who played by less than reputable means, putting Yuugi’s life on the line. Atem once more panicked, knowing that he could very well lose Yuugi in this duel, but his partner pushed him on, encouraging him the whole way. The only problem was, with every blow struck by Atem, Malik was losing more of his own life. This kept pushing into Atem’s mind what was right and wrong where losing was considered; if taking a life was alright when it meant saving so many.
Though once again his choice was deterred as he turned the tables on the spirit inhabiting Malik’s body. Instead of killing Malik, he sentenced the spirit to death, and Malik forfeited the duel soon after. After that, Malik revealed to Atem his destiny, carved upon his skin and told the Pharaoh what it was he had to do to regain his memories. The Sennen Rod and God cards were handed over to his possession and they went home.
The God cards were stolen soon after, however, and Yuugi and Atem set off to retrieve them. A new evil seemed to have caught their attention, seeking vengeance against Atem once more. Though this battle was particularly hard; during one of the duels with one of the henchmen, Atem was bolstered into using the very evil he was facing. Though his partner begged him not to do so, he refused to listen; failure heavy on his mind and refusing to lose. It ended up being his downfall, and as he was soon to be taken away and punished for his crimes, Yuugi stepped into his place saying that he believed in his other self.
Atem nearly lost his mind over this, swearing that he would get his partner back no matter what it took. Though the depression settled into his very being; he became nearly lifeless, droning about and regretting about losing Yuugi. It was only after he met up with Yuugi’s spirit and beat him that he realized he had to get his act together, it would have been the only way to save his partner. That was easier said than done, however; as his friends started to fall one by one to this evil, kicking him back more and more.
He teamed up with Seto once more at the final hour, and Seto risked his very soul to make sure Atem could win the battle. All alone, Atem nearly gave up- thinking this was it for him. His friends were gone, he’d failed to save every single one of them; and as Dartz spoke to him, trying to warp his mind, he finally realized that he would never be alone. His friends would always be there to help him; if only in spirit. He pulled himself together, making a victorious comeback and saving his friends.
They become very determined to start their final journey, to unlock the secrets of Atem’s past. Though Atem laments that he’s caused a terrible amount of damage to Yuugi’s life, to which Yuugi tells him to cheer up. They begin to make plans of going home and finally unsealing Atem’s memory. However a nick in their plan is found when they see that they have no way home back to Japan. Luckily for them, Mokuba shows up and offers them a ride with only one favor in mind- to participate in his brother’s new tournament.
With no other way, they agree. Though Atem is placed at the head of the pack; not having to duel anyone except the one person who makes it all the way to the top. During that final battle against a young boy named Leon, he faces a terrible strategy; a special card that has been altered to prevent being won out against. Despite being given this information, Atem refuses to give up, and when Leon tries to throw the match, Atem tells him not to. He tells Leon to keep fighting no matter what, even if it looks like defeat for the other party. It takes Atem time to think of several strategies, going through each one meticulously until he finally gets one right.
Finally after that, they head to the museum, ready to unlock Atem’s past and return his destiny to his own hands. As he faces down the stone tablet with the three God cards, his soul becomes separated from Yuugi and sent back into his original body- Pharaoh Atem. He wakes up in the middle of a meeting with his Sacred Court, though even there he still has no idea what’s going on. His memories haven’t been restored after all, and everything is very confusing. Though he becomes very curious, acting the role that’s been imposed to him; the story quickly unfolds, showing that the Thief King Bakura is out for his blood.
Bakura’s motives quickly anger Atem with his blatant disrespect and disregard for human life. Atem chases the thief, only to be completely overpowered by a scheme set up by the Priest Akhenaden. However, Yuugi and friends finally make it to the scene, holding Atem up and giving him that boost of confidence he needed. But cheating seems to be fair play even here, as time is turned back, and Yuugi ripped away from the Pharaoh.
After this, Atem wakes up to realize he’s sitting in front of a game board with Bakura at the helm. It’s quickly explained that Bakura is planning on reviving Zorc, and this “Memory World RPG” is the final setting for such a thing. They battle furiously, Atem all the while trying to figure things out little by little, and trying to stop Bakura from releasing the evil. Though this plan keeps getting thwarted, Bakura seeming to have the upper hand most of the time. Finally, he does manage to revive Zorc; and as despair hits Atem, he realizes now is not the time to give up.
He bands together with his High Priest, Seth, and Yuugi; using first Seth’s help to garner more power and together he and Yuugi summon the most powerful monster of light to seal Zorc. It was impossible to do this before, as Atem was alone- but figuring out now, he had his friends to help him, nothing was impossible. The game lost, Bakura thoroughly defeated; he finally realizes his destiny complete, his name, and his lesson.
It is then brought to his attention that he must travel back to where he belongs; to rest in the afterlife with his friends and family after having traveled through so much. It is said that he must be set free, and though Jonouchi offers to duel him, Yuugi says that they have to duel each other. This battle is particularly hard on both occupants; Atem relying a little too hard on his God cards becoming a crutch that Yuugi quickly disables.
As they wait for the final blow, Atem looks absolutely terrified, and Yuugi finally takes him down; falling to his knees in tears. Atem goes to him, reassuring him that this is what fate had in store for him, that it is his time to go, and not to cry over him. After all, this is not a loss; they’d shared so many times together. Yuugi dries his eyes as the rest of his friends begin to realize they are about to lose the spirit. As the doors open, Atem seems panicked, though his friends call out to him and he is finally able to smile; encouraging them that this isn’t goodbye, and that they will always be friends- he gives them a thumbs up as he resumes his place in the afterlife to rest peacefully.