Subaru died and returned in front of the door, he could open it, but it would cause Rem and Emilia to feel guilty so instead of opening it he went back to where Garfiel and Otto were.
"Where did you go Natsuki-san?"
"Ah, it's nothing I thought I heard a noise, but it wasn't anything."
Subaru didn't need to burden Otto with his problems. He knew he didn't deserve the love of Rem and Emilia, if they wanted to do that with Roswaal then that was fine with him. He was glad that they still put up with him instead of abandoning him, even after they realized that he wasn't [Natsuki Subaru], if he had to share with Roswaal then that was fine.
Subaru knew why Rem and Emilia had done that with Roswaal, it was because they realized that he wasn't [Natsuki Subaru], but why had Roswaal done that with Rem and Emilia? He didn't think that Roswaal was the type of person to do something like that, especially not with Rem and Emilia.
Subaru decided that he would ask Roswaal, but he couldn't do that right now. He could feel with Cor Leonis that they were still doing that. He would ask Roswaal when he was done.
Despite what other people believed, Subaru didn't hate Roswaal. He was thankful for Roswaal, without Roswaal Subaru would have never met Emilia or any of his friends, he would have probably just ended up homeless on the streets of the capital.
Subaru didn't blame Roswaal for the events of the sanctuary either, the only one who could be blamed was Subaru. Roswaal had only hired the assassins and summoned the great rabbit in order to make Subaru dedicated to Emiilia. If Subaru wasn't there then the events of the sanctuary wouldn't have happened and no one would have had to suffer. The reason everyone suffered at the Sanctuary was Subaru. Thankfully [Natsuki Subaru] was there to fix the problems that Subaru had caused.
Subaru could feel that they were done doing that with Cor Leonis, he waited until Roswaal was alone and went to meet with him.
"Roswaal I want to know why you were doing that with Rem and Emilia." Subaru wanted an answer from Roswaal
"Oh, so yooou finally fooound out."
"I assume you looooped again?"
"Yeah, I did. Now can you answer the question!" Subaru was getting annoyed with Roswaal.
In response to Subaru, Roswaal pulled out a black book.
"Thats ..." Subaru was interupted by Roswaal
"The Tome of Wisdom? Yes it is." Roswaal had dropped his speech pattern
"But I thought Ram burned it..." Then Subaru remembered Otto had it restored in Priestella.
"You thought I wouldn't notice when Otto-kun had it restored? After he had it restored I took it from him without him noticing, I have been following it since then. It told me to seduce Emilia-sama and Rem and do it with them."
Subaru was shocked, but before he could reply Roswaal began to choke him.
"I am sorry Subaru-kun, but I must do what the Gospel tells me to do." Those were the last words Subaru heard.