Originally Posted by
mootoall
The Aethenaum Nefarious is another interesting problem. Access to the Stronghold Builder's Guide might make it easier to make, but disregarding the physical aspects of it, which they player should be allowed to make up, how about it, like all other class features, scales with HD? It's a safe retreat the monster gets at, say, level 10, which gives a scaling bonus to all Knowledge checks? If you delay its rejuvination ability, perhaps say that this is the point where the Illurien's personal library has grown too big to carry, and now must be stored in its own, extremely magical building, which is created by the expenditure of a certain amount of time and materials, determined by a formula in the SBG?