after a certain point of having oppressed emotions and her relationship with her father worsening... even N could bring her up from the madness.... Uzi has had enough and she gets akumatized by Hawk Moth

Uzi: Don't tell me what to do, N... Yes..... everyone will pay.... they'll pay the price...

A dark purple ether surrounds and covers her until it disappears....Uzi is now Black Willow

Black Willow: ahhh....such a good feeling.....now it's time to make everyone pay....and be like me......and also world domination...... HAHAHAHAH