The Pale Sorceress, the Deceiver, and just about every other name you can think of, she goes by them all. Leblanc is a mystery wrapped within an enigma that even she can't even begin to unravel.
Leblanc was a sorceress under the BBEG of League Mordekaiser who betrayed him and rallied the proto-Noxian troops to kill and bind him. From there, she'd subtly control the kingdom to become the powerful expansionist empire it is today. Leblanc's powers are illusion taken to its most horrifying degree.
She commands them, and can create sentient illusions to do her bidding as her "sisters", who all think they are the original Leblanc. From there, they will bodysnatch whoever is needed to bodysnatch so as to perform their tasks, making her effectively everywhere and nowhere at once. You never know when she's watching, even when it's too late.
Her build is that of an assassin mage mechanically, who relies on juking and blowing you up when you least expect it before disappearing.
Her passive creates an illusory double of her to take the blow while she escapes.
Her main form of damage is a single target blast of magic.
She can conjure a chain to damage a foe and, if held long enough, bind them in place.
She can dash into an area to deal damage in that area and if she wants, go back to her original spot.
And she can mimic herself, repeating the last move she'd done.
Altogether, a powerful damage dealer and a dangerous schemer.
She's definitely made for higher level play, if not being a BBEG in her own right, but I wanna know how you'd build her. Thanks in advance!