Her name might be a reference to a Final Fantasy X-2 character with the same name. In the beginning of the game, she uses illusions to trick others as well.
LeBlanc's name in French literally means "The White". It could be a reference to the French mathematician Sophie Germain, who used the name M. LeBlanc to attend a university despite women in her times not being allowed to do so.
The reflecton in her old classic artwork is slightly different, possibly showing her old/true self, Evaine.
Leblanc's outfit is quite similar to Alisa Bosconovitch from the Tekken Franchise.
Prior to patch 3.9, LeBlanc's Mimic was the only ability in game that cost mana at rank one, but completely lost the cost upon reaching max rank.
Relentless PursuitLucian was the only ability that has that mechanic, until the ability's mana cost was changed to 0 at all ranks in patch 4.12.
Her joke: "For my next trick, I'll make their life bar disappear." is a reference to the common stage magician routine where the performer will make their assistant or some large object "vanish" in front of an audience. It could also be connected to the false leak of her abilities, where her ultimate made her team's life bar disappear for the enemy team.
LeBlanc's lines "Classic misdirection." and "Lying is, like, ninety-five percent of what I do." are likely references to the TV series Archer.
LeBlanc's line "Surprised to see me?" is likely a reference to the similar line spoken by Agent Smith from The Matrix Reloaded.
Her "For my next trick, I'll make their life bar disappear." quote is similar to Shaco's joke: "For my next trick , I'll make you disappear.".
LeBlanc and Shaco's joke is similar to a phrase said by Kefka from Final Fantasy VI.