I’m still catching up, but you repeated this so many times I have to put in. In the Warcraft story, there’s no particular association between the Lord of the Deep whose name you keep saying and undeath or necromancy. The Deep One is associated with themes of corruption, sleep and the sea. His brother, Yogg Saron, is the Old God associated with undeath and necromancy. The Hearthstone Card you’re referencing is nothing more than gameplay mechanic in a non-canon spinoff game.