terms:
backyard: it is another dimension, a dimensional space, resulted from the information conveyed from the backyard. Upon entry to the backyard, the extremely restricted data pressure is immense and anyone who enters must be "tuned" to the frequency the backyard emits in order not to be crushed by the dense information contained within it.
the barriers in backyard are so hax, they need to be slashed by certain weapons, since the layers, they are imbued with time manipulation essence and are on cosmic scale
within the backyard is an incredibly dense collective of information and data and no normal soul can survive for very long without being compressed under the pressure, so they must become 'tuned’ to the frequency of the backyard in order to survive
sol explains it as a world that can rewrite the laws of ours however it wants. The existence of the backyard was part of the system that defined the five main elements of magic
anything that happens in this world cannot affect the backyard, however, certain elements within the backyard can apply and change this world’s existence
normal people cannot enter the backyard since the density of the information there will crush them both physically and metaphorically
that man has developed a method that allows humans to remain in the backyard, and it is that method that allows sol, sin, doc paradigm, and izuna to travel there
In the core of the backyard is an isolated region called the cube, which was created by that man, and which allows him to exert his will on the world, the door/gate, however, was destroyed by sol
sol was never a backyard resident, but instead had his powers were “modified” to better adapt in backyard, after sol, is also the guy who has survived being erased from the timeline, when i-no destroyed his
past self in ggear core plus
master ghost: it is the manifestation of an individual’s soul via the soul sinker method, if the opponent find a way and destroy master ghost with high level soul manipulation, the person whom it represents dies, though that doesn’t seem to be the specific case with valentine’s master ghosts, which, by their appearance and use alone are proxies (given how powerful she is)
chord: originally attributed to music, but now refers to complex magic incantations. In music theory, a chord refers to any minimum of three notes played at once. Chords can be played as triads (three notes), quatrads (four notes), and as many as six notes at once, it’s a linkage of more than 2 tones.
cube: an artificial isolated space created by that man within the backyard that got the chord data on gears. Cannot be accessed without the key (prime field) of gear date and it is structured after sol's gear dna composition.
gears: they are magical bioweapons beings of mass destruction, the gears were originally created for the purpose of serving mankind either as a military force or for heavy labor, they had the intention to advance evolution, but were eventually produced as weapons for battles. After justice's rebellion, they waged a century long fight on humankind before the events of the series, and they were created by the gear maker = that man.
Overall, gears come in several types, species, and classifications: command, megadeath, normal, flying and prototype.
sol has kicked dozens of them, cuz he is that strong