Is Magic the Gathering a harmless game?

I had a friend in Connecticut whose daughter was being plagued by demons. She was normal in every respect. One day, she told me she saw a huge demon while she was riding in the car with her parents on the Berlin Turnpike. She said it was tall - around 100 feet. She was having strange nightmares and was visibly upset.

Her parents, being strong Christians, were puzzled as to why this was happening. God led me to ask her what kinds of games she was playing. She was about 12 or 13. She said she had these "Magic" cards. Here is what a sample card looks like: http://www.wizards.com/magic/PlayMagic/LTPnDemo-en.html

I asked her if she was willing to part with these cards if it would make the demons go away. "Yes!" was her answer. We told her parents and threw the cards into the trash. We then prayed over her and pleaded the Blood of Christ on her. She no longer has those scary visions and nightmares.