What is the ruling of Islamic law concerning the Dervishes who stab themselves with daggers and knives, saying "Ya Rifai" before "Ya Allah," and is there any evidence for their actions?

These are fraudsters and liars who use tricks to influence people. What they do, stabbing themselves with daggers and knives, is not real but rather an illusion for the eyes and magic for people. If they invoke Al-Rifa'i or others, this is major shirk (polytheism) and an act of worshipping other than Allah. Muslim rulers must discipline them and prevent them from these malicious acts.