Assassin champs like Akali and Kass get easily fed off of mistakes that low elos commonly make. Then they roam and snowball the game.
Rain Man literally went something stupid like 20/3 with Kassadin in diamond elo.
Voyboy consistently gets kills in the double digits on Akali
Diamond isn't some glorious haven of flawlessly coordinated players. They get pubstomped just the same as any disorganized solo queue match would.
You actually watch The Rain Man's stream? The kid is obnoxious and suffers from some kind of mental ***** --- Going to church doesn't make you a Christian any more than standing in a garage makes you a car.