Unlocking necromancer

[Gaidren]

Do you need to find all 4 "how to become a necromancer, part X" lore in the same game, or across games?

Where is part one? I found the other parts already in my current playthrough, but sadly killed the boss in the graveyard without having part one (had 2,3,4). Might as well know for next game.

[Mewtarthio]

You have to find them all in one game; however, it does count if you get them from the Fortress Library. Thus, if you've seen them across multiple playthroughs, you can just swing by the Library before fighting Celia.

As for where they are, I'm afraid they're randomly dropped.

[Gorgoras]

They are random, but i remember that i got all 4 without even beating dreadfell once. However it was a long time ago and it could've changed