Sinner may supplicate against his opppressor
4-10-2017 | IslamWeb
Question:
Assalaamu alaykum. If Allaah afflicted a person with magic or by being touched by jinn because of their sins, is that person considered to be opressed given that he is being harmed. In this case, if he supplicated Allaah against those who afflicted him with magic to help him against the opressors, will it be answered, like the supplication of one who is opressed, or is that not the case? May Allaah reward you.
Answer:
All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad 
is His slave and Messenger.
The person on whom a magic spell was done or who was possessed by jinn is included among those who are wronged, and if he supplicates against the person who did magic against him or caused his possession by jinn, then Allah answers his supplication even if he is a sinner, based on the general evidence that Allah answers the supplication of the oppressed.
Ibn 'Abbaas, may Allah be pleased with him, narrated that when the Prophet sent Mu’aath to Yemen, he said to him, "Beware of the supplication of the oppressed as there is no screen between his supplication and Allah." [Al-Bukhaari]
Abu Hurayrah, may Allah be pleased with him, narrated that the Prophet said, "The supplication of a victim of injustice is answered even if he himself is impious, as his impiety is upon himself." [Ahmad - Al-Albaani classified it as Hasan (good)]
Moreover, the Prophet said, "There are three people whose supplication will undoubtedly be answered (by Allah): the supplication of a just ruler; the supplication of a fasting person until he breaks his fast; and the supplication of one who has been wronged; Allah raises it above the clouds, and the gates of heaven are opened for it, and The Lord Almighty says, 'By My Might and My Majesty, I will support you (against the wrongdoer) even if it is after a while.'" [At-Tirmithi - Al-Albaani classified it as Saheeh (sound)]
Imaam Al-Qurtubi 
said:
"Al-Aajurri reported from the hadeeth of Abu Tharr that the Prophet said, '[Allah says] I do not reject it [the supplication] even if it came from the tongue of a Kaafir (disbeliever).' So Allah responds to the supplication of the oppressed, as he was sincere in his supplication due to his dire necessity, and because of the Generosity of Allah, and He responds to his sincerity even if he is a disbeliever. The same applies to the one who is dissolute in his religion, as his dissoluteness is upon himself, since the disbelief of the disbeliever and the dissoluteness dissolute do not undermine or decrease the Sovereignty of His Lord, so it does not prevent what He (Allah) decreed that He would answer his (the oppressed's) supplication."
If you think that this injustice occurred to you because of the sins that you have committed, as per the saying of Allah (which means): {And whatever strikes you of disaster - it is for what your hands have earned; but He pardons much.} [Quran 42:30]; then you have to flee to Allah and hasten to repent from your sins, and not commit them again, while seeking Allah’s forgiveness and performing good deeds.
Allah says (what means): {And whoever does a wrong or wrongs himself but then seeks forgiveness of Allah will find Allah Forgiving and Merciful.} [Quran 4:110]
Allah also says (what means): {But whoever repents after his wrongdoing and reforms, indeed, Allah will turn to him in forgiveness. Indeed, Allah is Forgiving and Merciful.} [Quran 5:39]
However, this does not prevent you from taking your right from the oppressor and supplicating against him; Allah says (what means): {And whoever avenges himself after having been wronged - those have not upon them any cause [for blame].} [Quran 42:41]
Allah knows best.