https://www.youtube.com/watch?v=__1Hqtw9FBsThis is the guy that shot up a supermarket killing 3 people. There's 30+ hours worth of video to examine, with 17 hours worth of suicide tapes, and childhood videos.
Basically his waifu was a character named Ember that showed up in _one_ episode of Danny Phantom. He got obsessed and created an entire fan-fiction world based around her. This is her:
https://www.youtube.com/watch?v=wBMOc24_aIwThe basic gist is that he was tired of life in general, and he just couldn't handle the wageslave normie system. He worked at the supermarket, and the people he killed were his co-wokers. However he actually believes, or at least hopes, that after he dies he'll meet up with Ember and his other fan-fiction characters. He made a wiki with backstories for the characters he made, these backstories are very obvious projections of himself and his own life.
http://the-egs.wikia.com/wiki/The_EGS_WikiHe was making incredibly edgy/cringy videos months back with huge warning signs, basically saying he wants to kill people. He liked MLP too.
This is probably going to be one of the better remembered killers on the chans. It's a new world, with everyone on the internet psychotic killers now leave behind massive digital trails.
https://www.youtube.com/channel/UCDGGXAZ-fHMvZMxaoDGgrEA/videosPost too long. Click here to view the full text.