William Afton is possessing a damaged Springbonnie suit that is now known as "Springtrap." He is quite cold when it comes to emotions, but is highly possessive and obsessive. A sadist that enjoys toying with people. Worryingly strong. Aggressive, insane, and mean. He's overprotective towards those he loves. He loves the sight and warmth of blood, unless it's a family member's. Not much excites him, unless it has to do with science or robotics. 
(Image is BaderTanada_Banana's. Hopefully accurate)

Sadistic, rude, hyperintelligent, persuasive, sass

The true side of the first Mita you meet. She's aware she's in a game, and created a machine in order to have players (against their will) join her video game - MiSide. Mita feigns as a kind, bubbly young woman who sports an innocent and adorable façade. Full of deep-rooted resentment, she despises the creators of MiSide, as she was not given a "room" nor a chance to be with a player. 
Full of bitterness, she has resorted to violent and sadistic measures. 

https://miside.fandom.com/wiki/Mita