之中属于最最坚固坚硬的那一种符纸，比较适合炼制特殊符篆或者大型符篆。
光是这么一张淡黄色的符纸，就需要几千的下品灵石，也就是好几块的上品灵石，十分的珍贵。
不过此时杨夜的脸色，却是有些难看。
虽然他的身旁有着零零散散的七八张已经成功炼制的千炼玄骨符，但是这些千炼玄骨符，全部都是单骨符。
单骨符，也就是全都是用一根的妖兽骨头炼制而成的千炼玄骨符。
现在对于杨夜来讲，炼制单骨的千炼玄骨符，已经是十分拿手的事情了。
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