Complex sentence: A new cosmetic addition was two long straps, similar to the ones that extended from the back of his mask, that dangled from his forearms, but the green gems and their placement remained unchanged with the forehead mount smaller in size.
Split into simpler sentences: A new cosmetic addition was two long straps, similar to the ones that extended from the back of his mask, that dangled from his forearms. The green gems and their placement remained unchanged, with the forehead mount smaller in size.