Fourteen used to be a loveable yet skin-eating Algebralien before being subjected to endless joy that The Darkness gives. They/he still eats skin.

When an Algebralien is infected, they have a wide smile and glowing white iris-less eyes, or just pure white eyes

Also, corruption spreads via; contact, getting bitten, and getting scratched.

and they won't stop or look guilty when they bite you because The Darkness made it so that they don't care about your feelings.