hold over someone's head

another nail in someone's coffin

An event that increases the likelihood of or causes further failure.

answer someone's prayers

To be or do exactly what someone has been wishing or asking for.

answer to someone's prayers

Exactly what someone has been wishing or asking for.

apple of someone's eye

The object of somebody's affections; a person (or sometimes a thing) that someone strongly prefers; a favorite, a loved one.

apron-string hold

An estate held by a man during his wife's life.

bane of someone's existence

Someone or something that poses a significant problem to someone.

bang one's head against a brick wall

To waste effort on a futile project.

bash someone's face in

To beat someone violently.