As for the remaining three skills 'Stellar Network', 'Dragon Scale Sequence', and 'Celestial Knowledge', they seem a bit excessive. 'Stellar Network' is a lesser Ether form, which can coexist with the primary Ether Theory; this should be Delan's own discovery. 'Dragon Scale Sequence', however, is an Alchemy Array group built on the foundation of the former—the so-called sequence, must be a combination of multiple arrays, its appearance somewhat resembles layers of overlapping dragon scales, hence the name.
As for 'Celestial Knowledge', it's not related to religion; it's merely a theory of studying the 'Floating Island Whale' from the Second World. Floating Island Whale, or Celestial Whale, Phantom World Dragon, all are its names.
It seems Delan's theory must have been inspired by the Phantom Dragon.
