User blog comment:SkyEyeKiller23/Black Blood Arts?/@comment-30011748-20131208181657

Sorry, but I haven;t heard a whistle about such a concept existing. But I think what you are referring to are the Level IV black icon Blood Arts that are unlockable once the golden icon Level IV Blood Arts on the same connecting path is unlocked. Those black icon Blood Arts are different variations of the move that it shares a growth path with and are typically stronger but with the cost of being slower to carry out.