okay yes he was a 72 year old man and it would effect him but there is nothing to go of to even include a young danzo and what about onoki hes probably the same age give or take and he stopped a meteorite with some help from gaara but then he survived the 2nd meteorite all well being an old man this alone puts him above danzo
no, ka was used because its danzo only way to keep up with sasuke and forbidden techniques shouldnt be tossed around so carelessly and the fact is danzo was not as skillful when it came to a fight with sasuke and if he was as strong as you make him out to be then all his izanagi wouldn't have been used up and if danzo thinks he can take on "madara" with only ka then he is just to full of himself
Onoki stopped a meteor so that makes him better than Danzō? Not at all. He merely has access to a Jutsu Danzō doesn't have.
KA was Danzō's only way to keep up with Sasuke? Obviously not, seeing how their fight lasted 5 chapters or so and he never got to use KA.
I feel you simply don't like Danzō because you are simply denying his power.
Fact of the matter is, Ay, Tsunade, and Mei have no counter for the Baku and Danzō outlasts Onoki.
You'll disagree, but whatever floats your boat.