Samara

Samara is the main antagonist of The Diary of Ryan Williams, and also the key figure of the storyline. Samara is a powerful psychic and were controlling the zombies that were attacked Lowell City and Summers Community Orphanage.

Samara's father, Alex used Samara as a "rat test" of Alex's new machine. But a mice accidentally bitten the machine's cables, making the electricity hits Samara and granting her psychic powers.

Fate
When Samara encounters Amber, Ryan, Pierre and Gregory on the Grayson Carnival View, Samara became panicked and began summoning numerous zombies to overrun the Ryan and the others, which results the death of Pierre and Greg, leaving only Ryan and Amber as the survivors.

However, as Amber managed to successfully shot Samara, another bullet came out from nowhere and were smashed Amber's bullet. A few minutes later, the screen fades to black along with a gunshot can be heard, along with a splattering sound.

Trivia

 * Her's father, Alex's fate is unknown, but it is speculated Alex were killed due to the electric shockwave came from the malfunctioning machine.