Derek Day

Derek Day is the secondary antagonist of the first half of season 1 and the main protagonist of season 2 and 3 in the slender series -Jeff Woods- and also the deuteragonist of SirensInTheNight.

-Jeff Woods- (Season 1)
Derek is Chris' older brother and the one who stabbed Jeff's brother, Liu. After seeing the madness that he and his brother unitentionally caused, he decided to hack the -Jeff Woods- account with the intention of proving that he and the rest of the gang are not the responsables for Jeff's insanity.

-Jeff Woods (Season 2)/SirensInTheNight
Still trying to prove his innocence, he makes his own video logs within the channel to show any occurences, he also finds about Edward Davis and his problems with the creature know as Reaperand the blue masks. After discussing with Edward, he had a brief fight with Jeff who suddenly appeared in the room, both he and Edward survived the incident.

-Jeff Woods- (Season 3)
After the fight between him and Jeff, he spends most of his time practicing for future fights. Derek's Multiple Personality Disorder Theory was confirmed when the video "DeathofJeff;-__'BirthofJeff|" was previously uploaded by Jeff, Derek created another theory as a result, The Virus Theory, saying that The Virus is controlling and protecting Jeff as his own creation, this theory was eventually revealed to be true due to the events of the video entitled "Protection", where he and Jeff had a fight once more, but this time Derek managed to shot Jeff unlike the previous fight as a response for fracturing Chris' spine, unfortunately for them, Jeff was saved by The Virus.