User blog comment:ImperiexSeed/The oldest being, archangel or leviathan?/@comment-184.77.255.73-20111214195052/@comment-184.77.255.73-20111216213527

I never said Lucifer/Jesse can't beat the Leviathans; they'd be hard-pressed to match a Black-Eyed Demon let alone an Angel.

Also, Lucifer isn't even CLOSE to his older brother's power, Castiel stated in a matter-of-fact tone that Dean would see nothing but Michael killing Lucifer which is significant because Luc was in his true vessel whereas Mike was in a pseudo-vessel.