SOLVED. YA - The love interest can change his face and body. [s]

[Meg]

So I borrowed this book about 3/4 years ago from a friend but can't remember the name or which friend I borrowed it from!

It's about a girl who maybe lives in a facility/lab sort of thing and has a best friend who is kind of a mermaid in a tank.

She meets this boy who can physically change into whoever he wants to be. He lives with his adoptive dad, his real face is white and featureless but he chooses to look like a younger version of the dad.
His name begins with an L I think? Something weird.

I can't remember much of what actually happens in the book though?
Title might have started with an E maybe?

Any help would be greatly appreciated! Thank you!

[Anna]

Paranormalcy

[Meg]

Yes that's it! Thank you so much, ya been driving me crazy!