As for inter-invasion, the link between the monsters of the third and the fourth was hard to establish, though one could say the monsters are varied anyways, and that this might be due to some missing knowledge. The link between the undead in the third and fourth invasion, however, seemed quite broken. The fourth invasion undead simply said "they were imposters", and left it at that. Again, maybe it's 'cause I'm missing key chunks of the lore, but undead beings that can summon thousands from the dead to fight again for them being called "imposters" didn't make much sense, as whoever they were, they clearly weren't kidding about having all that power. Melhed had also developed a lot of RP with the 3rd invasion undead, and I've heard them lament about how it had all turned into a blank slate. Summoner clearly had a lot of power over the undead, with his faction of the Necromancer's Servants, but obviously so did the fourth invasion's undead, so this break bothered me a bit.
The were impostors in the sense that they were not of "The Many". There undead state was not caused by the oaths that bind "The Many". They were undead, they could raise undead but they are completely different. What is wrong with this, why should there be only one source of undead? So far as I understood it the necromancers could not control the undead of "The Many" they created their own undead forces. Thus the label impostors.
