

Other than "because plot", if Claude wanted Ciel's soul so badly why didn't he just try to take it from Sebastian, like he already had done prior to the beginning of the season? It's not like demons and humans need to have a contract for the former to be able to eat the latter's soul.That said, the terms of the last order included that Sebastian would serve Ciel until he consumes Ciel's soul, and since he now has no soul to be eaten Sebastian is now stuck forever unless he wants say "screw it" to his aesthetics. Not going to lie, that is weird and if he wanted to Sebastian could really attempt to kill Demon!Ciel, especially since Ciel shouldn't have the experience to properly defend himself.
