You're probably heard that it's a Clarins 230 (a.k.a Unicorn Pee) dupe. I don't own Clarins 230, I would love to have one but would never be willing to pay the exorbitant amounts asked for it, so I'm extremely happy to own a bottle of Fantasy Fire! Finally we get a really cool and coveted polish in the UK!
Fantasy Fire is a purple based jelly full of shimmer and there's quite a bit of colour shifting going on (copper, green, red, maroon, gold etc) but these pics were taken under a lamp last night so I found it impossible to capture all the colours! The colours you get also depend on your base colour. Maybe a medium purple or blue jelly would create more colour shifts.
This is one coat of Fantasy Fire over CND Midnight Sapphire. Two coats of Fantasy Fire would probably give you more depth and make it look more dramatic.
Here is a pic in the style of Cristina from LTHP :)