I think it's really beautiful that Wifies was only able to see Levi because of his faith in Hummer
He didn't think the creature was real, but seeing how much it meant to Hummer for them both to see it made him believe.
In Schpood's commentary, he said that moment was fueled by one of Wifies' memories with his mother where she saw something beautiful one day while they were driving and by the time Wifies looked up to see, it was already gone, and it made her sad that he wouldn't be able to see it like she was able to.
And in Hell is the Absence of God (something this arg was inspired by) the main character can't believe in God, so he chases down something that will force him to love and believe in him, but when he finally is filled with the adoration and appreciation he was never able to conjure in the mortal plane, he is sent to hell parted not only from his wife whom he needed to get into heaven for, but also from a God he is now forced to worship and never again reach.
Originally after reading it, I could feel that there were parallels, but I couldn't root out anything distinct that would allow me to draw any conclusions on either characters' fate (neither of them were completely Neil, Ethan, or Janice on their own). But after some reflection, I think I may be able to hazard a guess:
Wifies is closest to Neil in everything but his motivation and his story's ending. He's hunting a creature because he needs an explanation. He doesn't care if he can't find the Leviathan because if he can't, then it's likely that it just doesn't exist, and he is annoyed but ultimately okay with that conclusion.
It's not until Hummer (who I suspect is like Ethan (and a little like Janice in the way he can feel Levi) in the way that he needs to know why Levi is out there)) begs him to believe that Wifies is finally able to find what he's looking for.
And Hummer's ending can go one of two ways:
The first is that he believes Wifies has given up on him. Despite the email he was sent, it's possible that after failing to find the Leviathan and seeing Wifies not return, Hummer may have believed Wifies had given up on him, forcing him to give up and block Wifies because he was unwilling to face his failure after pleading for trust.
But the more likely answer that draws the most parallels is that Hummer's fate was similar to Neil's. The potion of water breathing was Heaven's light and he died, knowing Levi was real and beautiful and all he'd ever dreamed of, but despite his complete submission to his beliefs, it still wasn't enough to get a glimpse of the object of his faith. He wasn't good enough, devout enough, to see the Leviathan, and he was left tortured with the knowledge that he may never be.
