It's also kinda adorable how both Unknown and Saeyoung react the same way to seeing the broken glass from the window. Despite having different motivations/reasons for being there, and regardless of how they feel for you, they both immediately react with concern and tell you not to move or you may get cut on the glass.
There is a difference here. When Unknown tells you to stay still, it’s because he needs you in one piece. You are something that he needs to use as leverage and he really doesn't have the time to deal with you if you wind up getting hurt. It's going to cause more trouble for him in the long run and he doesn't need that. He needs to use you against the RFA! He can't have you looking like you got beat up when he needs to use you as leverage.
He has to make sure that you are treated a specific way and that you are kept the way you need to be. You are a tool to him, he is not saying this because he actually cares about what happens to you. He cares about what happens to his tool. His eyes.
Saeyoung, however, cares about you as a person. It is normal for him to go out of his way to make sure that the people that he cares about or not hurts. He doesn't want you to move because you could get injured and in that moment when he sees his brother, there is too much going on for him to deal with that as well. If he had to deal with you with broken glass in your arms and legs, while trying to fend off his brother and the bomb, it would not have ended well.
It would have weighed on his conscience like a rock. He has to make sure you're safe because he promised that he would be your protector. He promised that he would be the person that took care of you while you're stuck in this apartment. It wouldn't be good for him to allow you to get hurt like that.
