Where does the jinn companion (qarin) go after the death of the human, and how can one fortify it to prevent sorcerers from exploiting it?

This matter is from the Unseen, and there is no evidence for it from the Qur’an or Sunnah. Allah has forbidden following that of which one has no knowledge. It is not possible to summon the Qareen (companion Jinn) to reveal a person's secrets. If anyone claims this, he is a lying devil and should not be believed, as the Prophet, peace and blessings be upon him, indicated in the Hadith of Abu Hurairah, may Allah be pleased with him: "He told you the truth, though he is a great liar. That was a devil." A Muslim should strive to learn what benefits him in his religion and worldly life, and abandon searching and asking about that which has no benefit.