User blog comment:IamJakuhoRaikoben/Sorcerer Magazine, Issue 50: February 2016/@comment-3424593-20160301060223

Ok for the riddle So I'm thinking the answer is a Magic or Curse, a powerful at that A magic/curse that has many forms so its like a Slayer Magic or Take Over Ok so it's a dragon slayer that was sent from the past and life before they came its a blur None of them have brown hair =_=...
 * A power overwhelming many others
 * Sometimes can't tell one from another
 * Life before a certain point is a blur
 * Hair brown like curily's fur

So I'm just gonna guess and say its Sting and Rogue because blond hair + black hair = brown hair? Idk XD