I like the term you used, "real shadow." Bitcoin is not an illusion in my opinion. As we know, it is a virtual currency that can be exchanged for other currencies, goods and services. If you can carry out feasible transactions with it, then you know it is as real as possible. The down part of it is its uncertainty since it isn't centralized and it is independent with no legal backing. I have Purchased bitcoins with the dollars, sold them and I have also used them for goods and services. This integration that the coin has with other paper currency is what keeps it real. It is increasingly becoming popular and accepted all around the world. You can even shop online these days with bitcoins. The people that lose from it mostly engage in risky investments.