I make Marriage A Grim Era and turn your Mother in law into a Woman Hitler.
If you have ever asked someone to "stop banging the pots", you have used me before.
What am I?
Marriage can be made A Grim Era if you rearrange the letters of the word Marriage........similarly Mother In Law can be changed into a Woman Hitler so, the only thing common in them is that the letters in them can be rearranged to form new meaningful words....and such words are called Anagrams which we are using in the given puzzle........