I swear I have never felt a more Demonic Energy at a concert than I felt at Imagine Dragons at Fenway Park last year. I have seen Slayer actual devil worshipers and this was much more palpable.
A - they were some sort of Ambassador's to Ukraine, B - the singer was promoting Therapy and Pharmacutical drugs to the audience. and C I was seeing one change into a demon on the big screen. It wasn't CGI and part of the show I could see their true form flashing in and out, it blew my fucking mind.