A set of innocent characters are made evil.
a) Garfield the cat (Jon is his human)
b) Sans (from Undertale who is mischieveous but now signifies turning something from good to wicked). Represented by the glowing blue eye.
c) Thanos from Marvel represented by the Infinity gauntlet), who has good intentions (to save the Universe from overconsumption) but his solution is to randomly wipe out 1/2 the population everywhere.
What makes it funny is the irony: Innocent characters who are actually capable of dark things.
It is a form of dark humor, where it is funny to be naughty / bad
What causes the quick laugh from an average 12 yr old in the USA is the recognition of familiar characters all put together unexpectedly.