undoer

Plural: undoers

Noun

• One who reverses or causes the ruin of something.
• a seducer who ruins a woman
  • "she awoke in the arms of her cruel undoer"
• a person who unfastens or unwraps or opens
  • "children are talented undoers of their shoelaces"
• a person who destroys or ruins or lays waste to
  • "jealousy was his undoer"
• Agent noun of undo; one who undoes.

Examples

• The ’UNDOER’ of his carefully planned word was a single, challenging ’X’.

Synonyms

destroyer, opener, ruiner, unfastener, untier, uprooter, waster