The ruling on praying behind one who slaughters at the grave, knowing that there is a nearby mosque for the people of the Sunnah?

Question:
I ask Allah to do you good, Your Eminence, father. The questioner says: A Sufi man holds mawlid celebrations, raises his voice with dhikr and supplications through microphones, and says, "I slaughter at the grave because these awliya (close friends of Allah) , and when I slaughter, I say Bismillah." He accuses the people of the Sunnah of declaring people disbelievers, and no matter how much he is discussed, he remains firm in his Sufism. So how should we deal with him? And is it permissible to pray the Friday prayer behind him? Knowing that there is a mosque not far away for the people of the Sunnah.

Answer:
If he slaughters at the grave as a means of drawing near to the grave, he is a mushrik (one who associates partners with Allah) committing major shirk (associating partners with Allah), and he is not a Muslim. His prayer is not valid, so how can one pray behind him? Since there is a mosque for the people of the Sunnah, go to it, and praise be to Allah. Yes.