Bill Cipher, βthe Book of Billβ:
"... I don't need anyone, I NEVER HAVE, and I DON'T MISS ANY OF THEM! I'M FINE!".
Fyodor Dostoevsky, βCharacter card letterβ:
βI'm always alone. And this is fine by me. Has been, and always will beβ.
Yes, they're both βfineβ. Only Bill screams into the void, and Fyodor becomes one.
So what do we have here? Two infinity-old almost-immortal demons, who destroy themselves just to prove they can be alone forever.
Spoiler alert: they can't. And they despise the vulnerability that's still left inside of them.
Well, at least Bill's in therapy. But he is also at the point of breaking. Fyodor is still holding on, I guess? But barely.