The School of Necromancy wizard's 14th-level Command Undead feature says (PHB, p. 119):
As an action, you can choose one undead that you can see within 60 feet of you.
If that undead fails a Charisma save, it becomes friendly and obeys your commands.
Unlike the spell animate dead, Command Undead does not specify that it has to be a Small or Medium humanoid. So am I able to attempt to command powerful undead such as liches, dracoliches, death tyrants, death knights, etc.?
I know that they would be hard to keep under control because of the saving throws and their high Intelligence, but can I try to use Command Undead on them? Or does Command Undead not work on them at all?