Invocations for when you meet an adversary or a powerful ruler
اَللّٰهُـمَّ إِنَّا نَجْـعَلُكَ فِيْ نُحُـوْرِهِـمْ، وَنَعُـوْذُبِكَ مِنْ شُرُوْرِهِمْ
O Allah, we place You before them and we take refuge in You from their evil.
References
[Sunan Abu Dawud - 1537]