KseBur

Web!Nil was a very low hanging fruit, but it fits them so well. Between lying, pretending, hiding stuff for ones personal gain (or because they just want to) to the very nihilistic outlook on life. I can imagine Nil agreeing with a statement that free will dosent exist and you can predict anyones actions if you just know enough info. There's also shared sentiment of arriving to a desired outcome with doing as little work yourself as possible. The Spider would also be usless without other people doing it's bitting and feeding it which fits well with Nil being a nitwit and being unable to survive on their own.

As to what fears Nil can fall victim to, it's also feels obvious. The lonely, the desolation and the hunt. The lonely could snatch them anywhere from the life in the village up until truly befriending Polly. Desolation obv zombie siege and whatever the hell is happening in the nether arc. And The Hunt is just a very villager thing to experience.

Another low hanging fruit is Johnny. Obviously avatar of The Hunt. One could make an argument for The Slaughter but it don't fit as well. It's obvious that it dosent matter to him what to chase, as long as you can chase it and if the situation devastating enough he will even turn on another illager (Polly) despite never doing it before, just like in the description of Hunt's domain in season five. Another compelling argument could be Desolation!Johnny, as in having such shitty and exhausting childhood that now he became an avatar and now brings devastation to others. But it doesn't feel as fitting. Just my opinion.

What fears could feed off Johnny is a more interesting subject tho. Maybe The Lonely? Having a pack or at least one partner seems important for avatars of the Hunt, but Johnny seems to be a bit isolated from the rest of illagers by the virtue of being "the crazy bastard" even in their opinion. And there was a time gap between him becoming a vindicator and Vinny getting promoted where he'd not have anyone close. Another one could be Desolation after the mansion fell. Vinny's death and Polly defecting did affect him emotionally.

Circling back to Polly I can't imagine them as avatar of anything really. As a pillager they could've served The Hunt or The Slaughter but they never relished in it.

They would be victim to The Desolation with the mansion thing obv, but I think they could also be affected at by The Eye. They always have some kind of "secret" they don't want others to know: the fact that they were spared by Steve, the fact that they was held hostage by a villager, the fact that they killed someone. To have someone or something that just KNOWS would be devastating.

Glen is interesting because I feel like she'll be "immune" to the fears. Like there's no real ground she can be approached at. Yes, she textbook definition walked right into The Corruption, but she wasn't scared, which is the point. Glen really is the mentally stable of the groupe. She's way to cool for this shit.

The Witch would probably be of The Stranger. Someone you knew now looking, acting and thinking completely differently. Or the Vast! It's associated with ozon smell and lightnings a lot. You can say that after being struck by lightning they had opened their eyes to a bigger picture of the world. Also avatars of The Vast tend to be it's ex victims, so-

The Trader... I'm split between serving The Stranger, The Vast or The Spiral. I think Spiral would be the coolest one for them tho. Strange person showing up in the weirdest places out of nowhere, with a weird aura surrounding them speaking of unrelated stories that don't make any sense, messing with your head. I can't imagine how possibly The Fears could feed off of them tho.

And lastly. Steve. (Probably) The Archivist serving under The Eye. Steve is always looking to know more and more even if it's to their detriment. They'll stay curios even if it hurts them. Also "You who watch and know and understand none. You who listen and hear and will not comprehend" is very them. If I had to pic others for them it probably be ether The Stranger. They human looking for other people in the world, but weirdly hairy, their speech is odd, they unrealistically strong and they can't die. Or, given the last point, The End. You can't kill them, you can't stop them only slow them down, you can't hide forever. They are inevitable.

Feeding on Steve the most would be The Lonely, for obvious reasons, and maybe a little bit The Buried? I think they would be the most "stuck underground and starved or choked on gravel to death" person in the world. The Buried represents social pressure as well. And Steve would definitely feel like they HAVE to do and be better with villagers after loosing Nil's village.