Talk:Dark Young/@comment-115.66.143.156-20161005045721/@comment-28167000-20161010215235

AHA! I found something (^__^)/

right after Ainz have summoned the dark youngs, he says: "This time round, the objective was to proclaim the might of Ainz Ooal Gown, a practitioner of super-tier magic, to the gathered nations. That objective had been achieved. However, letting these minions fade away would be a waste."

So Ainz thinks that they will fade away (just like the death knight). I can conclude through my re-search, that the dark youngs ain't mentioned ever again, so no-one can know for sure, if they are actually permanent or not.