Maria

Maria is an artificial creation who bears a striking resemblance to Jo and harbors a deep desire to harm her. Obsessed with taking Meg for herself, Maria confronts Jo, revealing that she is, in fact, Jo's "sister." When the two clash, their intense energies create a rift that transports them into an alternate space and reality. Though initially consumed by her violent instincts, Maria's defeat at Jo's hands reignites her humanity. In a final act of redemption, she sacrifices herself to protect Jo and Meg from the RAPT forces, ultimately falling in a hail of gunfire from RAPT Cybots.

(Source: Wikipedia, edited)