I don´t think Syd would kill any of them, because she would never kill someone just out of her personal reason...
But I think she´s expressed more than once that she´d really want to see sloane dead
When Sark is arrogant Cole is wayyyyy too arrogant! I hope Syd will kill him in S4! I think if Lauren is alive she should at least stay alive for at least 1 more season! Syd should kill her in S5!
I said Lauren but if Sloane was to ever die I would want it to be because he betrayed Syd yet again and she killed him. I know that sounds terrible but its the truth lol.