Kefka vs. Sephiroth

This reply to the poll is who I feel is more powerful. A click-and-vote is not enough to sum up who's more powerful, so I feel I must write this to do both villains justice.
I'm going to be completely unbiased and try to get my facts straight.

Kefka
Kefka started out as an upper peon in Gestahl's army, and was thought of as a psychotic clown to his peers because of an unperfected procedure of Cids esper-power insertion. To add to his powers, he captured Espers from the Esper world and had Cid drain them of their powers and imbued him with them. The only person Kefka was loyal to was himself and soon as power presented itself, he seized it. I'm speaking of the Warring Triad.
Kefka became a demi-God thanks to the Warring Traids power and shaped the world in his image.

Sephiroth
Sephiroth was formed by Professor Hojo and Lucrecia, but not through sexual intercourse. When Lucrecia was pregnant, Hojo injected her unborn child with Jenova cells and thus Sephiroth came into existence. Twenty years later on a mission, he defects from SOLDIER. Based on the Shinra reports, he comes to believe Jenova was a Cetra, and therefore he as Jenova's "son" is the last Cetra survivor. He also believes the human race had betrayed the Cetra 2,000 years in the past, leaving them alone to defend the Planet from a calamity it had faced (eventually revealed to have been Jenova itself), and resolves to take vengeance for his "ancestors". He then becomes unstable and begins destroying towns such as Nibelheim. He is stopped by Cloud and claimed as "killed in action" by Shinra. In actuality, he falls into a giant chasm that the Lifestream transverses. He is kept alive through shear will power and is sealed by Mako power into a crystal-like form. Over time, he regains his strength and gains even more of it due to the Mako power he's absorbing. He creates clones of himself to do his bidding and he continues to hibernate in his crystal form. Using the Black Materia, Sephiroth plans to call the Ultimate Destructive Magic - Meteor. The impact caused by Meteor will heavily injure the Planet, and Sephiroth will place himself at the center of its impact zone as the Lifestream emerges to heal the Planet's wound. Thus Sephiroth will merge with the Lifestream, becoming a god ruling over the Planet.
He is later stopped by Cloud and party before this can continue.


Conclusion
I am speaking completely unbiased when I say I think Kefka is more powerful. Here me out.
Kefka absorbed many of the Espers powers, as well as became a demi-God. The game didn't end and he wasn't stopped soon as that happened which seems to be a reoccuring role in many of the Final Fantasies. He completely devastated the world with his "Light of Judgement" and assumed control over the world.

Sephiroth on the other hand was born with the power of Jenova streaming through his blood. Once he found out that he was a failed experiment by Hojo, he went mad (not as mad as Kefka might I add) and attemped to destroy the world. FF7 was 3 CD's long and he was still not able to do what Kefka did.

In terms of power, Kefka's combined Esper and Warring Traid powers top Sephiroths imbued Jenova cells and his Mako energy he absorbed in the Lifestream.