The 400 night vision of Moon Shard as an item works during Bane's Nightmare, so instead of having 100 range vision during it, you have 400 range vision.

The 200 night vision of Moon Shard's buff does not work during Bane's Nightmare.

The 400 range shouldn't work either. Nightmare is thematically supposed to turn your hero completely blind, so Shade Sight working against it makes no sense. It should work against Desolate only.