Let's see, she did need Elone to go back in time(I think)
She needed a machine to start time compression
BUT!
She has the power of every sorceresses and adel was known to destroy a whole army with the simplest thought... o.o
She did end up destroying existence.

I think she is the most powerful person in FF history, really, who matches her?

She somehow managed to trick the party into achieving her status. And I think it's PIS that the party killed her...o.o

She easily pulled 3 planets and a large asteroid on the party(great attractor)... in her non ultimate form... take that sephy.
And she made her own ultimate magic, though I think it should have been stronger, or cooler looking at least.
She set the time in a time loop, though Garland did the same...
If she knew that squall was gunna kill her, she would have aimed at his head when she used Edeas Ice strike.


What do you think?
Oh, and please... We all know sephy is strong and cool but, he lacks in power compared to other bosses... Kefka destroyed the world... Sephy threatened the world with a meteor...
Kuja destroyed a planet... Sephy failed...

Story wise, Sephy is weak. After the strong support by fans, SE then buffed him up lol