Some words that can be made from the letters in PAINTER are:
therein
therein
therein
therein
Words that can be made from the letters in 'own' are nowand won.
therein
therein
Fidel Castro
therein
therein
therein
therein
The literary device of reversed words is called "anagram." An anagram is a word or phrase formed by rearranging the letters of another word or phrase, typically using all the original letters exactly once. It can be used for wordplay, puzzles, or as a creative element in literature.
Words that can be made from the letters in 'own' are nowand won.
Husndevi HUSN DEVI this is a Hindi word (There are no words in English that use all the letters you have given.)
therein
The There Herein Here Her He Ere Rein In (That makes nine.)