
I'm stupid who has the poison? I feel like Yvonne has it, which is gonna make pen look bad is she drinks it, cause pen wants to die.

That's right. Yvonne's maid (who is brainwashed) poisoned the glass. She eants to frame Penny. If you look you can see the marks that someone already drank from the glass, and that's why Penny said they were switched. So she can get poisoned instead, to not be framed, and, well, to die. Since that was her plan from the start
I think they're warping un the manga but I could have sworn there was a novel that went further no? I remember hearing stuff about his brother
Yes, the novel goes a lot further, Ray meets Eddy (the other emperor), Eddy and Jiskar obviously fight over Ray etc. Maybe in the side story
Maybe it will be in the side stories...