Opposite words for victim:
gainer, talebearer, taunter, assassin, tormentor, defamer, satirist, mocker, killer, tattletale, caricaturist, scoffer, lampooner, needler, parodist, ridiculer, gossip, troublemaker, tease, tattler, ribber, victor, scorner, torturer, libelist, insulter, libeler, harmer, derider, teaser, murderer, gossiper, winner, injurer, baiter, heckler, traducer.
Usage samples:
  1. Truly had she said, " There is no fool like an old fool;" for John Arthur had been an easy victim.
    "Madeline Payne, the Detective's Daughter", Lawrence L. Lynch.
  2. Oh, they can wait, when they have set themselves to trap a victim.
    "Anarchism and Other Essays", Emma Goldman.
  3. It is for an unfortunate child who is the victim of a horrible mistake.
    "Sant' Ilario", F. Marion Crawford.
  4. Oh, she was a brave woman, but she did have this thought as she went upstairs: If the child died she would know that she had seen a spirit; if the child got well, that she had been the victim of her own excitement.
    "The Mayor's Wife", Anna Katherine Green.