What is Achilles Complex?
1.
To have a Achilles complex is to wish or bring about death to those who have seen you at your weakest or have humiliated you in anyway.
A mild complex would just have you hate these peoples very existence but not necessarily wish for their death.
Taken from the character Achilles de Flandres from the popular book " Ender's Shadow" by Orson Scott Card
Someone sees you fail at something, you wait for them to be alone and no one sees the again, as they've seen you at your weakest, and your Achilles Complex has come into play
See