One of my main writing projects centers around a character rich with vices. Probably chief among them is self-interest, followed by dishonesty. When I say dishonesty, I mean more than lying to get by. This character is close-lipped about her past, goes by a false name, generally attempts to distance herself from her personal history. Readers are introduced to this character as she's living under a persona which she has constructed.
A major plot point involves her constructing a new persona in much the same way. Other major characters react to this in various ways, not all of them negatively.
I feel like I might have bitten off more than I can chew. I'm familiar with characters creating new identities (link to TV Tropes redacted), mostly as part of a villainous transformation. This is an idea I'm trying to play with, but I wish to present it in a less binary way. Shortly: the humble, virtuous identity is not less or more authentic than the grandiose, power-grabbing one that replaces it.
Is a character like this too complicated, too alienating? Does she require some measure of genuine backstory in order to function effectively as a disingenuous manipulator?