Oh, wow! A double-eyed geaas command! Shouldn't that be maybe twice as powerful as a single-eyed geass command? So at the most the gods would have been just twice as capable of resisting a geass command as Nunnally, and Euphemia was between a thousand and a million times superior to Nunnally if judged by the speed of breaking a geass.
Nunnally resisted but did not break a double-eyed geass command and broke a forgetting gess, while Euphemia resisted and defeated a command geass which was much stronger than a forgetting geass and thousands of times faster than Nunnally, so even if the geass commmand she broke was not a double-eyed one she still seems incredibly superior to Nunnally who in turn is probably superior to every other person that is considered to be merely human in the world of code geass. I think that is the very least that can be said about Ephemia's greatness.
I think it wold be advisable to give up trying to disprove Euphemia's greatness, before you end up trying to convince me and our readers that the gods were not as insignificant as some people think they were, that actually the gods were almost as great as Euphemia!
P.S. Shouldn't Lelouch have commanded the gods not to bring Charles and Marianne back to life? Wouldn't the gods simply bring them back to life as soon as lleouch left if the gods had even the slightest desire for Charles and Marianne to be alive? And if the gods didn't have even the slightest desire for Charles and Marianne to be alive, the gods would probably have killed them if Lleouch simply asked them to, without using his geass.
Thus Lleouch should have added "and never bring them back to life!" to his geass command if he wanted Charles and Marianne to stay dead. Perhaps he did and it was cut from the script for reasons of time. Perhaps the writers forgot about that and painted themselves into yet another R2 corner.
But if the gods were commanded to never bring Charles and Marianne back to life and had time travel capability they could resurrect them and send them back in time to Lleouch's era if they ever broke the geass command after countless millions or billions of years. So it seems they never did break the geass command and thus they were infinitely inferior to Euphemia in geass breaking ability.
If the gods did not have time travel ability they might not bother to resurrect Charles and Marianne after lleouch was dead and they didn't need to do so to annoy him. But that would mean that they failed to break their geass command before lleouch died, and thus were much inferior to Euphie in geass breaking ability.