Everytime the same core

Everytime I found a core in Itherian Realms, it is an Plague Surgeon core. Until now I found 3 of them.

Version: 0.5.8

Yeah, nemesis creatures drop those.

Every time the same? I think that is an mistake. Or is Plague surgeon an Itherian Creature?

its a unique core you can only get as a random drop from exactly one kind of nemesis creatures. other creatures may have other drops, not cores, definitely no mistake here. Its like rift watcher that you too, only can obtain in one specific way etc etc many things like that.