I am still gonna go with my gut feeling and say that Eren is gonna aquire all the titan powers and either give it all to Armin or take Armin's as well and then self sacrifice. I think Eren is separating himself from everyone and painting himself as the villain so that when he dies, it won't hurt as much for the people he loves.
I think most likely he will trust Armin to do the right thing. And that is why Armin is shown talking to Annie. Because he is explaining why he has to do what he has to do.
There is something off with this story. There are parts that seem like they were either translated wrong or something else. Like Shouta kept saying he was introduced as a girlfriend when clearly he wasn't. And About the pills thing too. It seemed like he was planning to use them on Shouta because who takes out the pills they DON'T plan to use and then sticks them in an easily accessable pocket???
Side note: If Shouta knew about the pills and said that he goes for men who do bad stuff to women doesn't that mean he had to have seen Hiroto with the pills with a woman before????
Anyway, I like the story and love this artist's style. It's really nice but the story just has some weird contradictions.
Pretty sure those were basically Viagra pills cause homeboy had issues getting or keeping an erection which is why Shouta said it didn't matter since Hiroto wouldn't be using his dick.
As for the girlfriend thing, this is likely a language barrier problem. He was introduced as a friend that was a girl... As in a girl friend, not girlfriend. Which is why Hiroto says "introducing you as a boy friend would have been weird" and why Shouta cried about being a friend Hiroto just had sex with.
Cuz cover girls don't cry after their face is made.
~(⁰▿⁰)~