Asslaam 'Alaykum
Bro, read the World of Jinn and Devils by Umar Sulaiman Ashgar:
https://d1.islamhouse.com/data/pdf-...ingle/en_the_world_of_the_jinn_and_devils.pdf
It should satisfy your curiosity inshaAllah.
Allah said in His Book:
"And whoever turns away from remembrance of the Most Merciful - We appoint for him a devil, and he is to him a companion. And indeed, they [i.e., the devils] avert them from the way [of guidance] while they think that they are [rightly] guided Until, when he comes to Us [at Judgement], he says [to his companion], "How I wish there was between me and you the distance between the east and west; and what a wretched companion." (az-Zukhruf: 36-38)
Allah doesn't appoint a shaitan over a person in the sense that He tells a devil to be one's companion, but what this means is that Allah appoints a shaitan over a person who turns away from Allah's Thikr by His Qadr (Decree) meaning: Just as one has turned away from Allah's Remembrance, Allah will then forfeit His Protection and allow him to be overcome by his enemy (i.e. shaitan) as a punishment for turning away.
The Jinn have power to choose like we do. Some are disbelievers and some are believers. Some are straight up devotees of Iblis and some are just sinful.
The jinn, like humans, operate in tribes:
"O children of Adam, let not Satan tempt you as he removed your parents from Paradise, stripping them of their clothing to show them their private parts. Indeed, he sees you, he and his tribe, from where you do not see them. Indeed, We have made the devils allies to those who do not believe." (al-Araf: 27)
Here we see again that if someone turns away from Islam and doesn't believe in it Allah, in His Qadr, will allow shaitan to overpower them. If a person turns back to Allah, he will enter again into Allah's Protection. The more we follow Allah, the less influence shaitan has over us and our lives, the more we neglect of Islam, the more influence shaitan will have over us and our lives.
For every person that the shaitan is able, he has someone from his tribe that he assigns to lead that person astray and command to do evil. If, for example, that shaitan were to become Muslim, Iblis will just appoint another one in his place. Also, that Muslim jinn will be at odds with shaitan and his Qabeelah (tribe).