I was on holiday in france and these two dragon type things developed in my head. They are the classic Yin Yang symbols where the black one symbolises darkness and the white one symbolises light.These two dragons rely on each other for survival. Whilst Light rests Darkness protects it by making their surrounding area as dark as night. Whilst Darkness sleeps Light protects it and makes their surrounding bright enough to blind anyone who comes too close.I have finally removed the lines from the original image and got it posted. Hope you like :).