Ben | Five
Ben might doubt himself enough to leave it at an 'I'll try', but Five was confident enough for the both of them. Sure, Five might not have been there for any of it, he might only know about his siblings due to their sister's autobiography, but he knew enough to feel that confidence through and through. Ben would try, and it would help. Of course, he was also of the mind that one could do everything right and still fail - that was simply life. A physical Ben would do more to help Klaus than nothing at all, period.
Five felt no need to linger either way. He'd said his piece, stated his gratitude and expressed what he could comfortably. Anything more would be unnecessary and a noticeable damper on an event he had no place being involved in. Ben was here, was physical, and while that was a curiosity in and of itself, it was obvious his brother could provide no additional information as to why or how.
As he moved to leave, a polite nod was offered in regards to whether Ben could help. He couldn't, not in this, but what caused Five to linger longer than he anticipated was the last statement. A returned comment of gratitude for his being here. I'm glad you're here.
It was a brief thing, but Five's expression turned to one of doubt before he looked back to his brother and he nodded. Congenital due to the moment, the nature of the conversation. The comment was accepted for that and that alone before he removed himself from the situation. He didn't know the person whose birthday was being celebrated, and even if he did, this wasn't the way Five would celebrate it. Might as well let those who were more inclined to such things enjoy themselves where and while they could, his brothers included.