Sabastian X Ceil | Unbreakable chain

Ceil Phantomhive has spend 2 years being served by his butler Sabastian after having the contract signed.lately,as death comes soon for ceil,he becomes distant from Sabastian thinking it won't do any harm,after all he is heartless.
Will it cause chaos to the mansion or will Sabastian take Ceil's soul with no hesitation?