Board Thread:Versus Battles/@comment-33029670-20190215162002/@comment-27123758-20190216000124

I don't think Griffin can kill Observer, and if he can, it won't be very easy. Even if he does, she can just resurrect... and she'll be adapting constantly. Acausality counters Griffin's precog, and Observer would be capable of forcing the concept of death onto him to counter his Immortality.

While Griffin has a lot of dangerous abilities and could feasibly incapacitate Observer for a while, Observer can slowly whittle away at his wards, copy/steal his abilities, and eventually absorb him. If she gets pushed too far, she will pull out Terminal Null, and, well...
 * In Never’s inner world, Terminal Null, causality simply ceases to function for anyone but Observer; permanence and consequence bow to Observer’s will, as causation, time, and space all freeze, preventing any action that Observer does not approve. Concepts cease to have any meaning in the face of this complete despair, destroying the basis of many magics outright, leaving most opponents helpless before Observer.