Dysfunctional Rules X: I Cast Comprehend Rules

[glass]

Tarrasque:

But...

Sphere of Annihilation:

Tarrasque is not a deity...

"Cannot kill the Tarrasque" is more specific than "can kill anything" so this is pretty clear case of "specific beats general", so it is pretty clear the sphere cannot kill the tarrasque. Is that a problem?

EDIT: Oh, I think I get it. If it doesn't kill it, there is no obvious way to determine what it does instead. "Nothing" does not seem like an particularly satisfying answer.