When someone only attacks the
one innocent person/part of a group and ignores the
people that actually wronged them.
This is based off of Levi Angstrom, a villain from the series Invincible. In said series, he has been a victim of evil alternate universe versions of the main character, Mark, these evil versions of have terrorized him in multiple dimensions and timelines. In an attempt to get revenge and
one bad experiment later...Angstrom decides to atrack the
one good version of Mark, and has no plans on stopping until this good Mark is dead, he even went so far to team up with the evil versions of Mark to try to ruin is reputation and
kill him.