The cost to craft the stones to corrupt your Celestial or Olympus Weapons are as follows:
Darkness Weapon Stone: 150 Darkness Shards, 2500 Archlight Tokens, 200kk Gold.
Darkness Equipment Stone: 50 Darkness Shards, 2500 Archlight Tokens, 200kk Gold.
Darkness Jewelry Stone: 250 Darkness Shards, 2500 Archlight Tokens, 200kk Gold.
(Dark Euryale)
(Dark Hydra)
(Dark Medusa)
Darkness Euryale:
Darkness Stheno:
Darkness Medusa:
Darkness Hades:
Darkness Lernaean Hydra: