The Mask of Loki brings the repressed sides of the person out which it turns them into their own person.
The Mask is everything Stanley wants to be such as confident, brave, charismatic and wild who is also a heroic person as well since even though he decided to become a gangster at first, he decides to become a superhero instead.
Eve like The Mask is everything Evelyn wants to be such as be loud, confident, flirtatious and wild who also like The Mask is a brave and heroic person.
Masked Dr Neuman is everything his unmasked self wants to be such as be childish, honest, aggressive, and having a sense of humor but doesn't want to admit it so he goes all psychotic because he is in denial that he exists and his unmasked self is not.
Masked Peggy Brandt is everything her unmasked self wants to be such as be egotistical, staid and being a diva.