The term Infiltration and asimilation is used when people infiltrate an organisation for a certain purpose. And the term asimilation is used more by the Borg than anyone else in this universe that i know of, however this is not reserved for military type of people and organisations it can also apply for an induvidual for example a person is injected with the compound of another being and carefully monitored over a period of time so that the implant may take over the person and control them completely, like having a cu det tat but for a person.

How its done when the choosen subject is voluntarily or invuntarily injected or implanted with the compound or organ or whatever it maybe that can do the job is succesfuly inserted into the person the hosts body begins to fight it as its a forgin threat that poses a risk, however since the thing is programed to make the brain think that its part of it rathar than what it actually is the body does not fight it instead it helps it to grow. If the technology is far advanced as it would be to do such a task then one single injection is all that’s needed to perfom the assimilation of the person, if not the organ or thing will need aditional suplments for it to grow, like orders for a stike team to take out its target and for that the people who initiated the operation will need access to the host at their choosing and they will monitor that their operation is going to plan, if it is an opertion with an unsupesting victim they will need to sneek in at night or when the host is not consious or aware of the actions perfomed on him/her. When the being is mature enough to carry out operations that it was sent for it will do what is told or order by its senders and to make sure that host is unaware of its actions it will carry them out at night to prevent getting cought by host, but 1st a foundation of isolation is needed to help the infiltrate the host must be islolated inorder for the thing to carry out its operations so the people that planted it will do their best to isolate the host from the world. 1 massive reputation destruction and the destruction of his/her freinds and cutting of or the family by means of sabotage and rumors. once all that has been done the being will take small opertions like taking control of the host while he or she is asleep. To take the person further it will slowly kill the host in his/her own body and once it has full control its just a puppet for the controllers.

Different genders of the host and the thing can pose problems for the take over if the host is male and the thing is female then the host will be held back by the thing from interacting with the opposite sex and thus to prevent the thing from dying or loosing power over the host. There is also the possiblity of biological transformation of the host to accomodate the thing such as the due going to dudess and eh becomes she unwillingly this will not happen over time as it’s not possible it would kill the host so it will take time. There will be visible pains in the most obvious areas of the host such as the genetelia and the chest as well as the face if it is a female that is the thing. Their actions will also change if anyone knows them personaly and if they have been away from them for a long time will notice a lot of change after meeting with them with gap of a few months or years.