Master Librarian

Over the early years of the series, Castlevania flirted with the ideas of the burgeoning Metroidvania genre. Exploration, adventure, and item management all were tossed around in games like Vampire Killer and Castlevania II: Simon's Quest. But it was in the PlayStation era that the game really codified all these elements -- wide, explorable areas, item collecting and management, and shopkeepers to sell you essential goods, into a single, masterful title: Castlevania: Symphony of the Night.

One of the key elements of that game, found early and used often, was the Master Librarian, a guardian of the Long Library who, instead of fighting protagonist Alucard instead provided aid from his shop. He managed items and knowledge, having collected both of his long reign in the library. Although ostensibly a minion of Dracula, the Librarian was more than willing to part with his information, and items, if Alucard had the coin.

The Master Librarian solidified a number of options that would become mainstays in the series after. He was a shopkeep, centralized and available at any time, with a variety of goods to sell and an inventory that would expand the deeper into the game the player got. He also provided useful hints and tips, helping players make their way through the game. And, finally, he'd provide information about all the enemies fought so far, aiding the players with this small bit of knowledge as well.

Curiously, the Librarian is the only shop keep featured in the true Metroidvania games who refused to buy back items from the player. While he would buy precious gems the players found, all other items in the inventory were stuck there, unable to be ditched, taking up space without providing valuable coin. This was a change that would be made with later shop keeps (like Hammer) as the series progressed.