[quote=@Bacon]
Wait a sec... both sith and nobodies have yellow eyes. Meaning a sith with a heartless could, assuming they are one in the same, exist separate from each other. (Translation; fighting Anakin or Palpatine's heartless while a protagonist duels the person themselves is feasible.)
[/quote]

Or we go the Pride Lands route and after Vader throws Palpatine down the shaft, his Heartless appears