User blog comment:Vaince321/Arc 1 Chapter 3:NJDS Part 1/@comment-25977712-20150111081223

NJDS is New Junior, Different Sensation(If anyone's having trouble knowing what it means). It also refrences to Achillies's first appearence by making Arthur feel pain the first it's awoken after killing few Aragamis. It now makes his heart feel heavier so it won't cause any problems to Arthur while fighting or talking.