Nektropos Lore?

Where can I find lore about Nektropos Castle?

The only thing I really have is the Flesh-Bound Tome that details Maltus Everling's discovery of the castle. Is there any other lore I can find out?

there's lots to find out about with Nek Castle. in fact, Maltus isn't the original owner, that would be Rikantus Everling. he wife and children died on him, and he spent a great deal of his life trying to bring them back/find them in Ethernere. the EVerling family business is dealing in cursed or otherwise afflictd trinkets, and the patron diety of the family is Ullorruuk, the Demi-Goddess of Betrayal.

Rikantus himself you've encountered a few times over the course of the game, as one of hte artifacts in the families possession divided him into fragments of his personality. like there's a merchant in Maj'Dul that is peddling wares..he's a facet of Everling. there's a merchant by the wiz spire in Feerrott, also a fragment. there's even a few in other places. you have to talk to two of them during the CoE sig line.

there are some collection books in Nek 3 instance, and there are bits here and there about Rikantus and what happened/is happening with him and his family.

Nek 3 is a real mess, but each version of Nek Castle has its own story it tries to tell. The Dolls of Nyth quest line also gives quite a bit of background on the castle. The two heritage quests in the castle don't really have much to do with its story unfortunately.

Much, much later in EQ2 you'll come across more on the Everling family. It is definitely worth spending a little time here so you can enjoy more of the story.