ok so i went through my old pics and you asked whats a Blue Core well...its nothing...i made it up in the series its this blue orb its the most powerful item in the world whenever one is chosen by the Blue core the Blue core goes into there hearts and grants them powers beyond imagination but you must master it first but theres many cores theres over 20000 cores known in my Blue Core series but they only know of The Blue Core,Red core,pink core,and a couple more the Blue core however is the most powerful core in existince...well thats all you get to know for now all of this is completely original and is my series btw dont ever say "YOLO" on my stuff im sick an tired of hearing "YOLO" all over the place