v.141 - Cygnus Awakening Update Highlights

You have to use the CS cubes if you want it to rank up.

I'm fairly certain the dusts that drop from monsters can at least rank the core up to the second tier, and can just as easily drop it back down, akin to event Occult Cubes and potential. I'm a bit too cheap to spring for both the CS dusts and solidifiers, so the free ones will have to do. :-(