Allaahumma Rahbas-samaawaatis-sab’i, wa Rabbal-‘Arshil-‘Adheem, kun lee jaaran min [here you mention the person’s name], wa ‘ahzaabihi min khalaa’iqika, ‘an yafruta ‘alayya ‘ahadun minhum ‘aw yatghaa, ‘azza jaaruka, wa jalla thanaa’uka, wa laa ‘ilaaha ‘illaa ‘Anta.
O Allah, Lord of the seven heavens, Lord of the Magnificent Throne, be for me a support against [such and such a person] and his helpers from among your creatures, lest any of them abuse me or do me wrong. Mighty is Your patronage and glorious are Your praises. There is none worthy of worship but You
Reference: Al-Bukhari, Al-Adab Al-Mufrad (no. 707). Al-Albani graded it authentic in Sahih Al-Adab Al-Mufrad (no. 545).
llaahu ‘Akbar, Allahu ‘a’azzu min khalqihi jamee’an, Allaahu ‘a’azzu mimmaa ‘akhaafu wa ‘ahtharu, ‘a’oothu billaahil-lathee laa ‘ilaaha ‘illaa Huwa, almumsikis-samaawaatis-sab’i ‘an yaqa’na ‘alal-‘ardhi ‘illaa bi’ithnihi, min sharri ‘abdika [name of the person], wa junoodihi wa ‘atbaa’ihi wa ‘ashyaa’ihi, minal-jinni wal’insi, Allaahumma kun leejaaran min sharrihim, jalla thanaa’uka wa ‘azza jaaruka, wa tabaarakasmuka, wa laa ‘ilaaha ghayruka.
Allah is the Most Great, Mightier than all His creation. He is Mightier than what I fear and dread. I seek refuge in Allah, Who there is none worthy of worship but Him. He is the One Who holds the seven heavens from falling upon the earth except by His command. [I seek refuge in You Allah] from the evil of Your slave [name of the person], and his helpers, his followers and his supporters from among the jinn and mankind. O Allah, be my support against their evil. Glorious are Your praises and mighty is Your patronage. Blessed is Your Name, there is no true God but You. (Recite three times in Arabic.)
Reference: Al-Bukhari, Al-Adab Al-Mufrad (no. 708). Al-Albani graded it authentic in Sahih Al-Adab Al-Mufrad (no. 546).