Tasked to bring a little girl to a slaughter house, an android who wants to be more human must decide between following his orders and deny himself emotions or experience emotions and kill his masters who are organising a genocide.

Sorry, rushed.... should read' you shouldn't use 'who'. Not until he is human, anyway.

Valentin, that sounds good. However, I would phrase it as 'an android that wants to be fully human, faceshis biggest....He is not fully human, so you should use 'who'.

Tasked by his genocidal masters to bring an innocent naive child to a quarantine camp, an android who wants to be more human faces his biggest fight: his new humanity.