Knight in Shining Armour
used to describe someone who saves you from a difficult situation
a well-mannered man who comes to save or help somebody from trouble
the term is used quite humorously as someone who comes to your aid
Thank you so much for fixing my flat tire. You are a knight in shining armour.
You saved me from having to talk to that tedious man. You are my knight in shining armour.
Don’t try to be a knight in shining armour you can’t save that drowning dog into the raging river.