L. Macbeth's Links
L wants to bring Macbeth to ruin, for no other reason than Macbeth is an easy target to manipulate. They don't feel bad for it either.
Macbeth sees L as her savior. She was lost before them, but now, she believes she has a purpose. Her purpose is to be loyal to L and bring up their social status by doing horrible things.
L has sex with Ceto and took one of Ceto's cards, knowing that Macbeth goes through their stuff. When confronted by Macbeth, L lied and said that Ceto forced herself on them and that Ceto must've planted the card to get L in trouble. Macbeth, believing L, now wants to kill Ceto.
L just sees Ceto as another pawn for their game of "Ruin Macbeth's Life"
L was a client.