User blog comment:KnocknickKnock/9 gates + master of the celestial realm/@comment-2.83.198.8-20131212210042/@comment-24264679-20131214013727

Actually they aren't theories the Celestial spirit king was stated to be the strongest spirit and he isn't part of the zodiac. Only the zodiac keys is made of gold material so the Celestial spirit king would have to be made of a different kind of material and it can't be silver because it was stated that there is more than 1 type of silver key per spirit and I doubt you have 2 Celestial spirit kings. As far as Silver keys being tools so far that is how the have been shown. Crux-The knowledge expert Lucy uses him for information, Hologium-The shelter and defense for Lucy she uses him for shelter, Lyra-The artist she uses her for music, etc. The silver keys have 1 purpose and are used more as tools. Ofcourse Lucy wouldn't call them that but and that's not what I am trying to say but that silver keys represent things like tools not that they are tools.

This is all based off of reasonable deduction. Also having spirits like Draco and co isn't theories since Hiro is taking them off the 88 constellations it has been proven multiple times.