Thread:BunsenH/@comment-28858167-20161019234452/@comment-26971439-20161020205913

the skyship i beleive never wants crystals. apparently the 2nd castle can upgrade to somewhere around 11 from what ive heard. crystals are a lot more useful now if you ask me, im always working on upgrading strucutres like my diamond extractor. crystals can also be used for the various vault upgrades.