I think what really gets me is that you can feel how frustrated Ilya is with his inability to communicate his feelings. He is SO eloquent in Russian and goes off on these long tangents about his feelings in his head and in his own language but when he tries to translate that for Shane it just… falls flat. He spends the majority of the show being viewed as this closed off guy who doesn’t speak much and doesn’t show much emotion (and even a notable chunk of the viewers see him this way??) but you can tell he’s incredibly emotional and doesn’t have the ability to express it in any way that would make him feel seen while also making sense to everyone around him.
It reminds me of the bit (I think from Modern Family??) where Sofía Vergara busts out with “Do you even KNOW how smart I am in Spanish?”, but in less of an “I’m being seen as less intelligent by those around me because of my accent” way and from more of an “I literally do not know how to word this for you and also not hurt your feelings or feel like I’m making you pity me” perspective.
And his home country, the place where anyone would understand him, is the one place he CAN’T fully express himself. It’s visibly crushing.