Is this because too many Isekai manga those Fae - (Tolkien) Elves overused or the pixie elves used for Christmas decoration that look really creepy?
Elves are hardly ever original and usually have some watered-down Tolkienisms to them, like being near immortal or extremely arrogant, (and being good with a bow). Then authors precede to fuck even this up, by not making the elves feel like experienced and knowledgeable creatures, just humans with pointed ears. Dark elves are no better because they are either elves but you changed the color palette or the edgiest thing imaginable.
So actually when the magic, red, fat man decides to come around for the pagan celebrations. I do enjoy the idea that was taken when thinking about those elves. They at least have some orginality.
I am not a big fan of watered-down monsters as well, many people decide to use monsters as obstacles or a way to gauge a person's strength. While the big monster fight that is drawn out is pretty fun I
personally prefer for the monster to have relevance as a plot device as well as being the creature it is in the world. The monsters in a story, to me at least, are as important as the hero or character. As it not only demonstrates a character strength or skill (or lack of said skill or strength), and not all monster encounters have to be violent but allows the author to determine how dire a situation is and it will also siminatanously set the tone for said encounter or maybe the entire story.