User blog comment:B214/High School DxD DX.4 discussion/@comment-31035098-20170701041155/@comment-10330822-20170714103405

Kind of makes you wonder if he did anything to prepare for the sealing. Like, perhaps he taught Sirzechs that hypnosis on purpose in advance so Grayfia wouldn't come with them, even though Sirzechs didn't know their fate. That way Millicas would have a parent after the battle.