Ghost writhe unique and eldritch battery don't function as I expected.

When wearing Ghost writhe with eldritch battery allocated I still have an energy shield, but just the energy shield from the 50% conversion. This may be intentional but it still lets me abuse a few energy shield mechanics while gaining the other benefits from eldritch battery.

On a related note any increase to energy shield that isn't flat will not increase mana by any amount while eldritch battery is allocated. This also may be intentional but feels heavy as it makes it very hard to scale and select nodes as any energy shield node is now broken.

Not a bug. If you view the Eldritch Battery node in the passive skill tree and hover over the word "convert" it clearly states that the conversion only applies to your base ES. It means that it converts ALL of your base ES. That doesn't stop items from converting life to energy shield after the fact, which is what happens in this case.

So order of operations as intended is:

1. Base ES is converted to mana by Eldritch Battery
2. Ghostwrithe or Atziri's Disdain convert life to ES
3. Everlasting Gaze adds ES based on base mana
4. Percentage increases from skill nodes are then applied to both ES and mana

These are intended interactions which many people have mistakenly interpreted as a bug because they haven't read the "convert" tooltip on the Eldritch Battery node.