Assassins Creed (Creed of the Brotherhood)

Descriptions of key items

History

"This... piece of silver cast out Adam and Eve. It turned staves into snakes. Parted and closed the Red Sea. Eris used it to start the Trojan War; and with it, a poor carpenter turned water into wine."
―Al Mualim about an Apple.

Long before mankind existed, the Isu, a civilization of technologically advanced beings inhabited Earth. They created humanity, and enslaved them by modifying their brains to be obedient in the presence of a Piece of Eden. For some time there was a forced peace, until two Human/Isu hybrids, Adam and Eve, stole one of the Pieces, an Apple,and incited the Human-Isu War.
As all were too preoccupied by the war to see any other threat, a major solar flare impacted the Earth, and significantly damaged both mankind and their makers. The Isu slowly became extinct, while mankind grew and populated the Earth, seeing their predecessors as myths and gods.

The Pieces of Eden were not destroyed by the blast, and throughout time humans began recovering them, also causing an ideological divide, resulting in the formation of two groups, now referred to as the Templars and the Assassins. It is the Templars' aim to restore peace in the way the Isu had once done – forced by the Pieces – whereas the Assassins, who fight for freedom and a flawed humanity, put free will above order.

Many decades have gone by as the war continues between Templars and Assassins, both knowing the importance of the Pieces – especially the Apple – to reach their goal.

To date, the Apples are featured as the most recognizable of the Pieces of Eden, being favored by Abstergo Industries in their plan of a New World Order, as some other Pieces were known to be able to create time paradoxes.

Powers and capabilities

"Those subjected to [the Apple]'s glow are promised all that they desire. It asks only one thing in return: complete and total obedience. And who can truly refuse? It is temptation incarnate."
―Altaïr's Codex, page 1.

A projection of humans being controlled with an Apple of Eden
The Apples were designed to be able to project images, conjure realistic illusions, and even turn thought into reality; hence, they were used by many great rulers throughout history, proving the efficacy of their powers
When the Isu created humanity, they bred within their brains hidden neurotransmitters.

The Apples can interface with these neurotransmitters to issue commands to the human brain, thus allowing them mental control over humans. However, humans with traces of Isu genes were not born with the neurotransmitters and thus were immune to the Apple's mental manipulation powers, but they were still susceptible to its physical effects. At times, those with mixed genes showed immense resistance —ranging from minor resistance to the point of outright total immunity— to physical control after coming into contact with its power. This was seen in the case of Altaïr Ibn-La'Ahad who, after being restrained by Al Mualim using the Apple, was completely unmoved and unharmed by its effects when it fell into the hands of Abbas Sofian. In modern times, humans themselves had already started research on the brain, comparing them to those of other animals, seeing that they were not like the other animals, but not knowing the reason for why
The Apple, as exemplified through King Washington's use, was also capable of emitting energy blasts similar to the Sword of Eden, albeit on a weaker scale. The illusions created by the Apple could also cause physical harm on the opponent, stunning them with a blast of energy upon contact. Furthermore, it was capable of influencing people even when no one was using it, an example being an illusion cast by the Apple in an attempt to influence Washington.

One Apple of Eden in particular has even shown the power to imbue objects with mystical power, given as how the Head of Saint Denis's power to cast terrifying illusions came from being empowered by it. During the Mongol assault on Masyaf, Altaïr used the Apple's energy to conjure up golden tangible-holographic apparitions of Assassins to repel the Mongol attack. During the alternative timeline of King Washington, he was able to use the apple to manipulate spherical balls of energy and even project blasts of energy.

All the Apples could presumably be used in conjunction with a Staff of Eden, though there is only one solid example: Ezio's Apple. Ezio Auditore da Firenze used the two Pieces of Eden to open the Vatican Vault, before taking the Apple, and losing the Staff as it was pulled into the ground.
Apples also contained knowledge of technologies used by the Isu. Like many other Pieces, they were able to "communicate" with people, showing them the schematics necessary to make the technology and transferring knowledge about the manufacturing of the shown devices. A good example of this was Leonardo da Vinci, who studied one of the Apples and invented four war machines, and several other weapons of technology far beyond his own time. There were only six known Apples, one of which had been destroyed in the DIA satellite accident.
When Isidora utilized the powers of Akhenaten's Apple for vengeance, the Apple unknowingly activated a curse, causing the bodies of deceased pharaohs to reanimate back to life.