Marcus' life before he died was... interesting in a sense. He was always taking things apart, usually by tearing them to pieces, even as a small child. It had worried his parents to no end, thinking he was possessed, no matter what the priests said to the contrary. As he grew older, he found he liked killing things as well, taking great pleasure in crushing small insects and choking or bludgeoning small animals to death. When he was old enough to leave home, his family sent him off gladly and barred the door in case he ever wanted to come back. Too bad for them he left a little present in his former quarters in the form of a small fire that wasn't contained. The house and all its occupants burned up sometime early the next morning.

Life on the road was less thrilling then Marcus had anticipated, but he knew that he could have much more fun while on the road. His life wandering the countryside was eventful, to be sure, but nothing really attention-worthy in his opinion. Sure he had burned a couple homes to the ground, and sure he might have kicked a couple (read: several) puppies, but it wasn't something he felt should have sparked the reaction it did. Which was either forced service in the Legion or execution. Naturally he chose the military. As for the main reason? He was being allowed to do what he loved legally. Why would he pass that up?

Life as a soldier in the Roman Empire was busy; most of Marcus' life was spent on the road and in conflict leaving next to no time for himself. But that was never a problem for him, as Marcus had a passion for something that made his comrades sick to their stomachs: destruction. It didn't matter how it was done, from destroying a body or burning down a building, he really had a knack for it. But it was never enough for him. He always wanted more. It wasn't long before it got to the point where his more ruthless commanders had him declared Immunes, a legionnaire with special skills and excused from labor and guard work. Naturally, destruction was the name of the game.

Marcus burned anything that got in his path, and nothing was ever enough to sate his appetite; but it all came to a head when he burned down an orphanage filled with children. It was in midst of the flames that one of his fellow Roman soldiers decided that today would be the day he avenged his family- it being one of his victims during his wandering days- and shot him in the back. Not expecting such an action, Marcus had grasped at his back and yanked the arrow out and looked at it. He turned around, trying to locate the source but found another arrow going through his heart this time. By the time he realized what had happened he was already dead, his body consumed by the encroaching flames.

When he found himself outside his body, his first thought was that he had triumphed over the fool who dared to attack him from afar. But it didn't take long for him to discover that he couldn't touch anything, or that no one could hear him, no matter how loud he shouted. He tried to vent by yelling loudly and throwing things at people, but was, sadly (for him anyway), only partially successful. As the days turned to weeks, he would watch gleefully as lives were destroyed, families ruined, homes burned, yet still he wasn't able to participate in the 'fun'. As he watched a family be burned alive in their own home, a thought occurred to him: why should others be able to partake of this and not me? And so he grew angry, and little by little the chain attached to his chest grew steadily closer.

As the days count grew so too did his rage grow, which only served to hasten the chains encroachment. His envy of the living for being able to do what he longed to eventually drove him to the brink, and his chain became smaller as it retracted itself into his chest. Once during a fit of rage he came across a great hulking. . . thing that towered over him that, upon sensing his presence, chased after him. Knowing he had no chance against it, he turned and fled the other way, grumbling all the while about how he was going to get back at it for this disgrace. It took a while, but he eventually manged to lose it, but he was irrevocably changed from the encounter, his chain's length been cut in half. By the time it finally disappeared entirely, he had long since grown past caring about it, and so did his heart disappear also.

15 years had passed by the time he became a Hollow.

The moment the chain disappeared, a hole appeared in Marcus' chest, and he began to scream. He had never felt such pain before, and as it increased, he felt himself become covered in a white substance that seemed to become a part of him, and then he found himself growing taller, wider, stronger then he was when he was a human, with a hunger to match. A mask formed on his face that he found he could manipulate. Marcus found he liked his new form, and, after learning that he could now affect the physical world, quickly put it to use. Nothing was safe from his hunger for souls and destruction, and while he lost himself somewhat to his new animalistic tendencies, he was able to retain enough of his intelligence to stay in control.

His fearsome smile oozed murder and mayhem, and his resulting actions only brought that reality home. Nothing survived when he put his mind to it, and many innocent souls were consumed in drive to fill his hole as well as his lust for desolation. Marcus consumed tens of hundreds of souls in his rampage as he tried to make himself whole again, but no matter the number, nothing seemed to fill his thirst. But that was when things changed. As he consumed the rather bland-tasting soul of a pregnant mother he was set upon a person wearing a black robe of some sort wielding a blade that actually hurt him. Sure he had been attacked before by some of the more spiritually aware, but they either fled or were consumed in the end. This one, however, actually managed to cut him, and in his arrogance lost his arm to the sword-wielding humanoid. Having gone so long without any challenge he had grown complacent, and stopped training himself. The result of this decision never more obvious than then.

Screaming in rage at the loss of his arm, he reached out quicker than the swordsman could react and plucked him up into the air, firmly in his remaining hands grasp. He screamed angrily into its face before he leaned over and bit its head off, its body following soon after. And that was when he discovered something more delicious then any run-of-the-mill soul, and he quickly came decided that he was going to find more of these things and eat them too. For when he ate that single soul he felt more whole then he had in years.

But the tasty morsels got smarter, and his crusade for better sustenance proved fruitless. Until, in a fit of rage, after gathering the strange power he had found within himself and slashed the air before him, causing a rift to open. Staring at it for a moment, he decided that wherever it went it couldn't be less aggravating then where he was now, and so he leapt inside, the portal disappearing behind him as he went.

He found himself in a land of endless night, where creatures not entirely unlike himself roamed, some were bigger than he was, while others were the size of humans. And yet, for all that he associated humans with weak, he couldn't help but feel intimidated by those smaller beings and so went out of his way to avoid them. He came across a forest during his aimless wandering, and found things weaker then himself, which he was more than happy to consume, and so he ate  and ate and ate until he felt something strange inside himself.  Others converged on him in an attempt to devour him, but in the midst of all the fighting, he devoured enough of them that he and other Hollows in the area found themselves glued together and growing into something truly massive.

By this time, another 2 centuries had passed.

Marcus' sense of self became clouded as the entity moved through the forest, but not enough that he wasn't in control, and so he was able to continue his feast of his fellows, that he now knew to be called Hollows, and this time he was going for other Gillian, the class that he now was. It was a hard slog, as he fought against the mass of other Hollows and the hunger for more increased. One Gillian after another would fall before the slightly intelligent colossus. In his lust for more, he ventured outside the forest, but he overestimated his own power, and finally bit off more than he could chew. He happened across an Adjuchas-class Hollow and he barely survived the encounter. He became wary of venturing beyond the trees after that, but not of devouring other Gillian.

He kept up his consumption of the large Hollows long after his defeat, and by this point his consciousness had assumed complete control. His mask changed shape as well, reflecting his ascension to master of the lesser Hollows within the Gillian. He continued to consume other Hollows, not letting up until finally he felt himself change again, and this time, he grew smaller instead of bigger, and his intelligence grew as he returned to a more sentient state.

Another 2 centuries had passed by this time.

Marcus' time as an Adjuchas was fraught with challenge. His body shifted, becoming shorter, changing from 5 stories tall to human size, the hole had in his center had shifted positions and was now situated over where his heart used to reside as a human. Consumption was the name of the game as he kept a tight rein over the many clamoring Hollows within himself, each crying out for control. He became more rabid, not stopping for a moment lest he slip.

His powers also grew in this form: his Ceros became more powerful, his ability to manipulate fire became more evident, as well as the ability to create Gargantas to the Human World. Marcus, in an attempt keep his newly acquired power, would seek out others of his and take them into himself. His abilities evolved over this time, allowing him to defeat greater and greater foes that found themselves lost in the mass that was Marcus' body.  Centuries passed, and for all that he hungered, nothing seemed to truly sate it, but that did not mean that there was no way to.

As he continued to eat, some of the other more intelligent Hollows endeavored to leave him alone, especially since because he was so much more powerful than many of them. His Adjuchas form was also more potent than many of his fellow Hollows. Power was all that he cared about, and, as he now considered his existence as a human a time of weakness, decided to toss aside the name and took up Thanatos, Greek god of death. For so was he the harvester of souls.

His evolution brought a bit of difficulty, however, as for all that he was more powerful, there really was nothing for him to do, because there was no driving need to become more powerful as, while he knew he wasn't invincible, was at his peak, and he found that the Vasto Lorde's weren't numerous, nor were they easy to find. So he had to settle for whatever Adjuchas-class Hollow wanted to try its hand at defeating his evolved form. Not that it ever ended in their favor. Centuries passed, and the Crusades had long passed by this time. Thanatos watched passively as the humans attacked each other again and again for petty reasons such as religion or land. He only became interested when they would decide to wipe out a group of people, such as in 1307 when the Knights Templar were demonized by the Roman Church and all over Europe the once-revered warriors were cut down simply for existing. It was the highlight of the century for him.

By the time 1470 rolled around, Thanatos had been a Adjuchas for over 7 centuries, and a stranger approached him and offered him more power than he could imagine. Intrigued by the offer, he accepted. And quickly found his mask ripped off his face, introducing a pain like nothing he had ever experienced.

When the pain subsided, Thanatos felt something he hadn't for over a millennium: his face. His enthusiasm at being able to quickly disappeared as the presence of a sword was noted at his side, something he had not expected in the slightest. He looked curiously at it, wondering what it was, until the stranger informed him it was called a Zanpakuto, a blade not unlike the ones used by Shinigami, but its function decidedly more dark.

He was led to a fortress named Las Noches, a location that he had avoided not out of fear but more because he wasn't interested in seeing it burn. He had witnessed several such structures destroyed and it had gotten old after a while.  Thanatos walked inside the fortress, and upon meeting others of his kind was given tentative membership with the Espada, as all the positions the time were already filled and he had no interest in killing one to get in. And so, although a very powerful Arrancar, he did not become a member of the Espada until the aftermath of the Day the Black Sun Set.

One day when Thanatos was bored, he decided to venture out into the Human World to see if there were any interesting wars going on, but instead happened across a Shinigami that, while she seemed reasonable, had no interest in leaving him be and attacked him on sight. The two clashed blades again and again, neither giving an inch, but it wasn't until she slashed him across the chest due to underestimating her that he flew into a rage and unleashed his Resurreccion and burned her to ashes, the Shinigami being unable to withstand the intense heat of his form. This was the last time he would be seen without chest-armor.

2 centuries later, Thanatos found his part in the Setting of the Black Sun glorious, in his opinion at least. Thanatos hadn't been able to let loose in ages, and took great pleasure in cutting down his foes. He even participated in the slaughter of a couple Lieutenants that cried as they fell, joining the symphony of despair rising above the battleground. Nothing deterred him; he kept cutting through Shinigami after Shinigami, always stronger, always dominating, never giving them a chance to retreat. His desire for destruction overshadowing his senses as he drove through his foes. When it was all over, three of the Espada had fallen, but that only allowed him to join the ranks, which was something Thanatos was just fine with.

The calling of the Arrancar back to Las Noches was something unexpected, but then, the former Adjuchas didn't have anything else to do and so he answered the summons, journeying back to the fortress he had inhabited for over 2 centuries. With the need for new Espada to replace the fallen, Thanatos was accepted into their ranks and became Espada numero Septima. With the rise of the new King of the Hollows, the Hollow's place in the world was swiftly changing, and it wouldn't be long before their revenge would be had, and the fire that would turn their enemies to ash.