Dark Brew talent says:
Your attacks that deal Nature or Bleed damage now deal Shadow instead.
If you enchant your weapon(s) with Authority of Storm:
Your abilities have a chance to imbue you, causing further abilities to sometimes unleash lightning which deals 141135 Nature damage split amongst all enemies hit.
I would expect this proc to be shadow damage instead, but it’s not, am I missing something here? Is this a bug?