Maybe I'm remembering wrong but I think Guy Burt answered why Yassen stayed alive in the TV show once and it was essentially - yeah Thomas Levin was just too good as Yassen 😆 And I love that so much
Is that not why everyone was so fixated on Yassen despite him only really showing up in like 2 books to begin with - such a damn good character it's a shame? Anthony Horowitz wrote a whole book for him, the only AR book not Alex centric because he missed him- and I think he even said its his favourite. There's an insane amount of fanfic. He's widely considered as one of the mainest of the main characters. The movie felt it was important to give him more scenes and have him hang upside down from a helicopter. And then , when he showed up in the TV show, it was like well we can't just kill him can we? He's just too bloody good a character (and Thomas Levin!!!)
I felt the vibe I got from Levin as Yassen right from the start was shark eyes. Like his eyes are dangerous, they're flat, they're dark, like a shark's. I'm not sure if that makes sense to anyone else but regardless, I think we can agree that he plays Yassen in a way that just screams danger and competence and perfect Yassen yet he's also different to book!Yassen in that he's not quite so expressionless but the way he judges people and his silent sass is hilarious 😆 and I think it works perfectly visually for a TV show.