It turns out that GIMP can blend pictures! You just have to add the image selected - to an alpha channel and make the picture you want to blend, a seperate layer from the main picture and then use the erase tool to erase the parts you want blended while having the layer you want to erase selected. Another thing about GIMP is the magic wand, it doesn't select areas as well as paint shop pro but careful attention to detail can easily erase that problem.
The main downside to the later paint shop pros and its adobe counterpart is the extreme lag that comes with all those files it uses to operate but the results you get can be awesome. My info is about 4 years old however and computers may've gotten better in accomodating those programs, in refference to how much space it has and how fast computers can process information nowadays.
I honestly can't tell whether or not you blended the images. If you did, I'm even more impressed. Though the one with the skull face and the bright blue color look awefully suspicious. A mod for Halo maybe? xD