For now all Fenrir can do is suffer. But the day will come when he runs free, howling in rage at his betrayal, his upper jaw knocking the stars out of the heavens and his lower dragging the depths of the sea, to bring death to Odin.
How is this Odin Fault?
Fenrir was born to kill the Odin during Ragnarock event. Since, Fenrir is a God and son of loki is cannot be killed. Odin is just saving himself. All of us will do the same if we knew h who is going to kill us.
But it's precisely by trying to save himself that he precipitated Ragnarök and his own death. If he hadn't been so horrible to Fenrir, the wolf wouldn't have had any reason to want him dead.
"this is a literal beast of the end times, and he will rampage during the war and ragnarok, devour the sun and all the stars, and maul the gods and root out yggdrasyl"
society: "oh, poor puppy, here, let me take of those these binds"
Well, I mean, Fenrir didn't do anything wrong and was co-existing peacefully with the aesir until they betrayed him because he was getting big. On top of that I think you'd also be pissed beyond reasoning if all your friends tied you up, stuck a sword in your mouth, and left you for alone for years. So yeah actually, poor puppy.