I've been reading even more about Kenny Dennis
and ended up finding the script for an entire movie
(you have to click About). It is quite the read. I read it all despite the annoying gimmick animation playing on top of it.
It swings between ridiculous and funny and depressing and too-real. There's even "a let's get the band back together for a benefit concert" scene. The appearance of this comforting trope gives you hope, only to pull away to a really dark truth.
I am incredibly impressed by what Serengeti has done with this character. He could have kept him simple and pure in order to not put off everyone that liked the Dennehy song. Instead, I think he followed the grain of the character, even when it went somewhere less fun.
A story like this bites harder when it is about a character that at first seems bright and problemless. This is how things often unfold in life, too. Big happy pop stars turn out to have a lifelong history of depression. A guy in viral video with a funny accent turns out to be a serial abuser. A confidence-building invisibility ring turns out to be a phylactery and beacon for an evil demi-god.