LeBlanc's loading screen and in-game icon are the first to not focus the actual champion (they focus her Mimic)
Mimic used to be the only ability (currently Relentless Pursuit) that ended up costing 0 mana when fully-ranked.
LeBlanc, Shaco, and Wukong are the only champions with more than one texture per skin (one for themselves and one for the clone spawned by Shadow of the Rose, Hallucinate, or Decoy).
Her byname LeBlanc means "the white" in French and is grammatically masculine (expected feminine form: *LaBlanche).
In her new lore, this secretive, ageless Pale Woman betrayed her superior, the warlord-king Mordekaiser & former ruler of the Immortal Bastion, to the barbarian invaders who would later found Noxus, LeBlanc being only one among her many aliases.
She would later inexplicably manipulate nations to war against each other for centuries,for instances, she masterminded the Noxian invasion into Ionia.
In the old lore, Emilia LeBlanc is not an individual but a mantle, with the current one (Evaine) being in charge of the underground society 'The Black Rose', whose members include Elise, Swain, and Vladimir.
Leblanc had helped Boram Darkwill to Grand Generalship, only to 'betray' him & be executed by Darkwill's loyalist Swain.
After staging her 'death', she falsely promised the decrepit & mentally unstable Darkwill with immortality & convinced him to send Swain to his death or disgrace in the disastrous Ionian campaign.
Still, Swain survived & discovered the truth; he then violently usurped Darkwill's throne with a newfound power & subjugated the Black Rose, at least for the time being.
In her old lore, LeBlanc set the stage for Swain's ascension to Grand General of Noxus.
LeBlanc had spearheaded Sion's initial resurrection (assumedly by dispatching Elise to the Shadow Isles, where she first met Vilemaw) and the current one managed to restore his mind with Jarvan IV's blood (the hemomantic ritual was conducted by Vladimir)
How she obtained the Exemplar's blood is unknown, but it is suspected his capture and imprisonment was led by Swain and then she herself impersonated the prince to avoid suspicion from Demacia.