whomsoever
/ˈhuːməˌsuːɛvər/Definitions
1. pronoun
used to refer to a person or people whose identity is unknown or unimportant
“The door is open to whomsoever may enter.”
2. noun
a person who is chosen or selected, especially for a particular task or position
“The committee appointed a member to investigate whomsoever was responsible for the mistake.”