Finding a Friend

So I have someone i friended a while back. His account name is Leo. I really thought that was a cool name and so one day i was gonna ask him if i could have that name. (he finds a new name and i get his) but the day i was gonna ask he never got on. And he hasnt been on since. SO i was hoping if someone on his friends list might have some way of contacting him. Or in the VERY remote chance riot does see this that they could give me some way to find him. I AM ON NA.