EleventhPhotograph who does 90% of my cosplay photoshoots and always does a fantastic job! :)
This process of splicing hoodies will only really work if the sweaters are the exact same size and brand, as the zipper halves have to work. Always check in the store that the zipper of one half sweater will zip with the opposite. It is also much easier if you can find a sweater where the hood isn't lined, otherwise you have to deal with the lining too.
I measured and cut them in half (first pulling the drawstring out of the hoods!), and unpicked the channel for the drawstring on the hood at the center top. Then I sewed the left and right halves to the opposite coloured hoodies. Then I stitched closed the drawstring channel on the edge of the hood closed and finished the center back seam I had created. I put the drawstrings back in the hoodies. Presto! Two black and white hoodies! ;D
When this was done she took them and machine embroidered his logo and catchphrase on them! Very nice! :D