Off topic but I had an argue with my That friend some moment ago.. she's blind even I have shown the proof but she says she finds happiness in th*m..I have no words to confront others
I believe when showing these types of things to people it is best to show them very gradually. Just saying a small thing here and there to catch their interest, but you need to wait for the right moment to elaborate on these types of things. It is a lot to take in especially since the fans have consumed themselves so deeply into idols. I am not sure of your religious beliefs, however, if she is Christian remind her that idolatry is a sin. It goes against the second commandment.
“You shall not make for yourself a carved image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them nor serve them. For I, the Lord your God, am a jealous God, visiting the iniquity of the fathers on the children to the third and fourth generations of those who hate Me, but showing mercy to thousands, to those who love Me and keep My Commandments."
Fans can are so consumed with these idols because their spirituality with God is missing so they consume themselves with obsessions and addictions. It can happen to anyone and it's not only k-pop fans who go through this, however, anyone is vulnerable when they do not have a good relationship with God.
Right now your friend is very vulnerable. She is going through many conflicting moments. Keep your friend in your prayers and have patience with her just as Jesus had patience with us because he loves us. Do not create arguments over this it is essential that you be reasonable. Show her evidence, tell her your opinions, tell her what you have read and researched, however, you must be patient. Tell her the history of secret societies and that they have existed for millennia so it is perfectly possible that the elites would desire the company of BTS or BTS themselves since Bang Pd is the 6th richest man in Korea right now. Riches and money are surrounded by evil things it creates greediness and gluttony and it encourages sinful actions.
Remind her that BTS was never there. Did they hold her hand? Did they wipe away her tears? No. They only took her money and time. They do not love her so her happiness in them is just temporary happiness, not true happiness.