Día 15 de enero_ Hay momentos en la vida en los que quieres rendirte, dejar de luchar, pero cariño, toca tu corazón ¿Lo sientes? Estás vivo por una razón, no puedes rendirte, sé fuerte.
—  365 Días, Miles de Sonrisas.
MysterySkulls--Ghost Headcanon

I know I’m late to the program, but I finally got around to watching the video today, and, like all of you know, it’s phenomenal. But after rewatching it repeatedly due to my obsession with it’s brilliance and reading up on some of the fandom’s theories, I have my own to add!

Many of you believe that the cave had some sort of incarnation that haunted Kevin (yellow/orange) into pushing Lewis (purple/pink) into his rocky grave. But here’s the thing. We see at the start of the video Kevin has a metallic arm.

At first, I thought, “Cool, amputee representation, what up!” But wait, there’s more! Later on, I noticed something weird about the mirrors and reflections when the trio falls through the Wonderland-esque trap.

Kevin has no arm in his reflection! Whaaat?!?! Now the pup (whose name I can’t remember, so I’m calling him Red) has no reflection due to a cracked mirror. (You can also see that Viva/Vivi [I’ve seen both names used] has no eyes in her reflection. I’ll get to that in a bit.)

Now then, during the flashback, when Kevin pushes Lewis, we see quite a few things going on in this one scene. Red has this creepy silhouette ordeal going on, and Kevin’s left arm (which in the future/present is his metallic arm) is starting to be discolored/haunted/possessed/controlled. (This is also the scene that many of you have pointed out that Viva managed to see Lewis die—though she didn’t actually have the vantage point of seeing that he was pushed. I’ll continue on this idea soon.)

This is where everything gets a bit too real. When we flashforward to the present, we see this lovely demon-fox (Kurama). Though I noticed him every time, it wasn’t until I finally paused it that I noticed he is holding an arm in his mouth. Oh gee, I can’t help but wonder if it’s Kevin’s arm! Also, he has the same diamond creepy eyes that Red had during the flashback when Kevin was possessed. This confirms when the video plays for another second and we see:

So, Kevin didn’t mean to push Lewis at all. In my headcanon, Red/Red’s inner demon possessed Kevin to kill Lewis. Since Red possessed Kevin, his reflection was cracked because of the demon. Since Viva saw Lewis’s death, her reflection has no eyes. And since Kevin committed the act, his reflection has no arm.