Neverwinter: The Year of Deep Water Drifting
Shard of Night
What if the Shard of Night is actually the broken-off top of the Tower of Twilight?
Maybe there was a battle between a Selune-worshipping Harpell and the Sharrans of Xinlenal some time during or after the Spellplague?
If the Shard of Night is restored using the Tears of Selune, perhaps it connects to the Tower of Twilight once more?