I think that what sebastian wants is for ciel to get his revenge so he can take his soul as said in the contract. If he wanted a broken soul he would have make sure to break ciel. If you remember, in cp 94, when ciel lost his memories and didn't want to do anything sebastian was going to eat his soul because he abandoned his revenge and before he was going to eat his soul he said "it's not was I was hoping for but it might fill me a little", which means his soul will be more delicious if ciel will fulfill the contract and get his revenge. Also, the title of cp 95 Is "an unsatisfying dinner"
If you read chapter 63, Sebastian said when our ciel gets his crown decorated with despair. Sebastian wants our ciel to get his revenge and it will be more delicious when at that time he will be left with nothing. Everyone who he fought alongside being dead leaving him alone again. Anyways that's my prediction.
I think as time goes on our ciel will loose his friends one by one and left alone to despair just like what Sebastian wants