Sinister, dark, gothic, and horror are all subjective terms. What one person finds horrific someone else might find cute.
I think the Reaper V1 is cute
Death is fairly unambiguous, but the representation of it can affect different people in different ways.
I've only found one keycaps that I could not even look at pictures of, can't remember what it was called (which is a good thing) - it had what looked like little pipes or arteries sticking out of it at random angles. Something like that would totally gross me out if I had one on my keyboard, but a Reaper is saying, like, "hey, look at me, you want ot click this switch, dontcha"
)