: Where does it say it was his greatest secret?
Man, now I can't find the reference, but I know I saw it somewhere talking about how Soulblighter rediscovered what was Balor's greatest secret, the reanimation of the dead, and blah blah blah...
: Not quite common knowledge; the Baron Kildaer was an
: unusual man. I'd say he only taught mebbe two or three
: humans. The rest of the reanimation was done by
: Shades.
But, as seen in GURPS, undead are all over the place and people frequently summon them. I imagine that those human associates who aren't already dead taught it to their court wizards and such so that they could more quickly make more undead, and in that was the powers of necromancy have spread.