These are the steps below...
First o all we must create the hub that will hold the fan blades.. SO we create a sketch in any plane we want....
Then we revolve to create the hub... (can be done with extrude... its up t you..)
Next we sketch the fan blade, as it would be flat...(like before the pressing)
Then we extrude it.. (NOTE we do NOT merge result because we want to modify the blade before adding it to the hub)
To continue, we click on the flex feature, located in Insert->features->flex and we select the blade as a body to flex... We choose twist option from the menu.
we adjust the twisting planes in order to twist the blade in the desired direction...
After twisting, we are done with the blade treatment, and we circular pattern the blade, as a solid body. (we pattern the blade body)
Finally we combine the blades with the hub....
and the result is a simple fan:)