In the module Out of the Abyss, there is a stat block for Orcus (p. 245). The part, describing the abilities of his wand, says:
While holding the wand, Orcus can use an action to conjure undead creatures whose combined average hit points don't exceed 500. These undead magically rise up from the ground or otherwise form in unoccupied spaces within 300 feet of Orcus and obey his commands until they are destroyed or until he dismisses them as an action. Once this property of the wand is used, the property can't be used again until the next dawn.
So, my questions are:
- Is he allowed to choose the undead he summons? Similar effects of some spells for players doesn't allow to choose specific creatures, only CR, but can Lord of the Undead do it?
- Is he capable of summoning specific named undead, like, for example, Acererak? Orcus conjures them, but it's not clear if they are teleported from the Abyss or created on spot.