He considers himself in the same group, which is why it amuses him. He may talk like a privileged Coruscantii but that was something he'd picked up and trained himself to use. Enough stress however and he reverted back to his natal accent.

"I tried to get Obi-Wan to leave, on Mustafar. For old times sake. You don't have to agree with someone to not want them harmed." And they period was certainly Vader at a level of delusional, paranoid, and violent which hadn't been topped. He'd been more like a feral predator than anything. "Padmè had friends who were Separatists, she and one even brokered a truce and peace between the CIS and the Republic, before Dooku assassinated Bonteri but had they been successfully, the civil war would have been over barely a year into it and Palpatine would have been forced to step down a Chancellor." Did he mention how much Palpatine hated Padmè?