Greek Mythology

Greek Mythology (ギリシャ神話) is the mythology of the ancient Greeks. A large part of Roman mythology is derived from Greek mythology and it forms the foundation of what is known as Classical Mythology.

Principles
As a mythology with a pantheon of gods, it operates similarly to Norse Mythology. As gods of polytheistic religion, they have emotions similar to those of humans such as love, justice, fear, and jealousy, and having doubts and failures like any one else. These gods aren't perfect, and such as when combined in a single group, complemented each other's weaknesses, creating a single flexible system, a sturdy defense system that could not be overcome by any foe.

Like a number of other mythologies, the primary deities, or theoi in Ancient Greek, of Greek mythology, the Olympians, are a younger generation of gods who fought against an older, more chaotic generation of gods, in this case the Titans, conquering them and taking their place as rulers of the cosmos.

Background
In the past, as is often the case when people encounter other cultures and are faced with something they don't understand, the ancient Greeks, who had pride in their own intelligence and culture, and believed themselves to be the world standard,, such as with the Egyptians and their mythology, resulting in interpretations of cultures which mixed in their own biases, misconceptions and preconceptions. These interpretations and other European misconceptions have resulted in a distorted imagining of Egyptian Mythology spreading and persisting to the present day.

As the Greek age led into the Roman age, Greek lands and culture were absorbed by Rome, resulting in Rome's indigenous mythology being overwritten in the process.

Though pure Greek mythology-based Magic isn't used much in the main story of Toaru Majutsu no Index, it has been mentioned as a potential magical format, and as one of the many religions and mythologies which have caused Phases to be created over the world.

Greek mythology was one of several fields which influenced the development of Hermeticism, which would become part of the foundation of the Golden Dawn.

Coronzon Arc
During the invasion of London by the Crowley's Hazards, the defenders deployed Divine Mixtures, capital defense spiritual items derived from interpretations of Egyptian Mythology distorted by the Greeks and based on combined divinities of the two mythologies.