Uh, the outside shape of the mask is fine except the nose bit is going to look very, very awkward with a shape like that, remember you have to try and imitate the art.
And the eye shapes are not tall enough, they have to be smaller and wider I think. and it doesnt really have a straight edge at the bottom so you're going to have to fix both of those things then after that go right ahead at the next step :3
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To be honest, it's probably easier cropping the lighter size of the mask, then rotate till up-right, and then just scale it big enough for it too look nice on the toris head. after that ( i know the picture will be all shitty quality, just redraw the shape of it and where the eyes should be etc ) this will give you the exact mask shape , It isn't really a cheap way considering you are still going to be doing the art you are just using it as a guide line and then copy + paste it to the other side too , ( I don't mind the head being symmetric as it probably should be ;o )