>>44479799Mary Sue has a meaning, it's just misused by people who don't know it what actually means, which is a character that plot/universe bends over backwards to accommodate.
What determines a Mary Sue is how the plot treats them. With normal characters, the plot comes first and characters bend to carry out the story. With Mary Sues, the character comes first and the "plot" is written around the character and bends to their every need.