this is less headcanon and more me just talking abt canon god eater biology stuff for my own sake ( and to have a place to point people at if they want to know what the fuck i'm talking about ), but, hey.
god eaters โ and adaptive god eaters, or AGEs โ are, essentially, humans infected with an aragami.ย aragami are hives of microscopic semi - sentient cells (ย oracle cells, specificallyย ) that take the form of monsters, and their only instinct is to devour everything, including each other and, in some cases, themselves. aragami will naturally eat almost everything, but things they won't eat are referred to as "bias."
the only thing that can kill an aragami / can destroy oracle cells is another aragami / other oracle cells. hence the creation of god eaters โ only people who are also sort - of - aragami / people who are infected with oracle cells โ can destroy aragami.
to keep the oracle cells within them from literally devouring them, as oracle cells are wont to do, god eaters all wear a large armlet that is perpetually infecting their body with something called bias factor, which essentially twists their biology into being something that their particular arrangement of oracle cells think is too like them to eat.ย getting this armlet installed ( ย and therefore becoming a god eater ย ) is incredibly painful and almost never a choice someone actually consents to, and, if this armlet is broken, the person will become โ painfully โ an aragami.
due to the fact that AGEs are not only god eaters but also built to have an extreme resistence to ashblight โ a form of poisonous miasma thatโs covered most of the world โ they wear two armlets.ย one on one arm which infects them with bias factor to keep the oracle cells in them from devouring them, and one on the other arm which offsets the ashblight infection they were given.ย if that armlet was destroyed or removed, their ashblight infection would suffocate, corrupt, and kill them.ย better than transformation into an aragami, probably, if nothing else.
(ย the double armlets also enable them to be used as restraints, which is โ another can of worms. ย )
beyond that, god eaters also have weapons which are specifically designed for them; or, perhaps more accurately, god eaters are designed for their weapons.ย god eaters and AGEs use living weapons called god arcs, which are mechanical weapons infected with oracle cells โ only oracle cells can destroy other oracle cells, so only god arcs can destroy aragami โ which, you guessed it, means that these weapons possess a constant need to devour, just as aragami / oracle cells / god eaters do.ย as a general rule, people are forced to become god eaters when a god arc becomes available, and when they are made into an AGE or a normal god eater, they are specifically programmed with a bias factor that matches the god arcโs โ if one without that specific bias factor tried to use the weapon, the weapon would devour them alive at best.ย one god arc, one god eater.ย god arcs can devour aragami, which in turn gives more power to god eaters โ many god eaters, especially AGEs, view the line between their weapon devouring and devouring something themself as one in the same.ย they eat the aragami as much as their weapons do.
this is all to say that god eaters are built to devour and, in some cases, be devoured.ย they are so extensively modified that, especially in the case of AGEs, thereโs very little difference between them and aragami any longer.ย god eaters are made by injecting them with what makes up aragami, and they wield weapons that are extensions of them that functionally are aragami.ย god eaters are their god arcs, they are their oracle cells, and AGEs are all that as well as being more aragami and also being the ashblight infection.ย i just think thats sicks as hell.