well you see, the LT can se the future, so he knew what he was about to happen to those FOOLS....but against someone that can control time itself(HOTU, IG) its more complicated....
Gender: Male Location: somewhere within time & space
The CN and UN attack differently.
The UN nullifies the space-time of an area.
The CN nullifies the actual life-force that supports the space-time of an area.
Eternity's spirit (his life-force) survives after a UN hit, (on panel)
nothing is capable of surviving after the CN hits, it turns space/time into unspace. (on panel)
The CN erases Eternity/infinity completely, not the UN,
because the UN only affects what Eternity/Infinity support (space-time)
but not their life-force (Eternity/Infinity's consciousness) like the CN.
With that said, Galactus gets erased, and there's nothing he can do to stop it.
Gender: Male Location: somewhere within time & space
The CN wasn't created to restart reality,
it was designed to utterly erase the life-force of reality from ever being.
It's true, the CN has only demonstrated nullification on a universal scale,
but look at who it has been capable of nullifying, 238 Jaspers. (an omniversal threat)
And Roma was going to use the CN on HOM Wanda, would it have worked?
I can't say, but the writer made it seem as though it would.
When you can erase someone on the level of 238 Jaspers,
and can threat someone like HOM Wanda,
who cares how much space-time it can take out.
That aside, the CN also has omniversal range,
the UN hasn't demonstrated via feats or statements
that it can affect anything outside the prime Multiverse.
With the LT intervening it would be kind of cheap to say"ok this guy is bad so go kill him"then the comic is over.Just because he is strong doesn't mean that the comic writers are just going to send him in to save the day again and again.
__________________ Some men, just want to watch the world burn.