Sephiroth isn't terribly amazing either, though Jenova itself is pretty freaky.
Sephiroth can use all of JENOVA's abilities. So I'd say he is pretty "freaky" as well.
I was evaluating the characters in terms of impact on the story and the strength of their character rather than on raw, physical power. I suppose using the latter you're correct, but I stand by what I said.
Not my words Carol, the words of Top Gear magazine.