come what may

ain't what it used to was

Is not what it used to be; (expressing nostalgia).

as they come

As it is possible to be.

blow to kingdom come

To totally destroy (something); to annihilate or wipe out (something).

Christmas come early

Something very delightful or fortunate that is happening or has happened, especially earlier than expected.

come a cropper

To suffer some accident or misfortune; to fail.

come a long way

To make significant progress.

come across

To give an appearance or impression; to project a certain image; to seem or appear (to be some way).

come again

A polite formula used when one has not heard or understood what has been said, or to indicate surprise.