User blog comment:KnocknickKnock/9 gates + master of the celestial realm/@comment-24066070-20131208182752/@comment-87.165.126.39-20131214174401

caelum seems to be much more usefull for mages like angel. you could clearly see that she was still able to stand after lucys uranometoria. but then she took the weapon herself and shot once - afterwards she was exhaunted. so my guess is, that it needs magic to summon it, and then either magic (the canon) or muscle power (the sword) to wield it. so the strength of caelum depens on the mage using it. even more than any other spirit.