The sparrow is a rare drop from the Morgeth encounter.
The ghost shell is rare drop from any of the encounters.
The ship is a guaranteed drop for special chest between Morgeth and the Vault. It only appears after entering in wish two at the wall of wishes. It can only be opened with a glittering key, which is a rare drop from final chest.
One Thousand Voices is a rare drop from the final chest.
The raid specific mods have a chance to drop alongside a weapon or armour peace from the two hidden chests in the raid. They are below the bridge between Kalli and Shuro Chi, and on the cliffside between Shuro Chi and Morgeth.
The Glittering Key is used to open a special chest between Morgeth and Vault. The chest only appears after entering wish two in the wall of wishes.
The Wall of Wishes is used to make wishes using Riven's power. It allows you make several changes to raid ranging from spawning an extra chest, to skiping to specific encounters, or adding special effects and extra narrators. The path starts just outside the doorway that leads to Kalli.