Mimic

A Nei which allows its user to mimic another Caster's Nei and use it as if it was his or her own. This form of Nei appears to be quite peculiar and extremely rare.

The specific mechanics behind Mimic are as of yet unknown;

it's unconfirmed what the user has to do in order to copy other's Nei or how many types of Nei he or she can have at his disposal at a given time.