How come everyone says that shiva does 9999 damage but when I got her she..

Shiva only does 9999 damage when yuna is really strong so it doesn't matter yet. As yuna grows so will your aeons

I think it's because your magic power is not as strong as it can get.If you get your magic power way up, and if it doesn't work, well think of it you got your magic power all the way up and now strong regular magic attacks will do 9999 damage.

The damage of an aeon depends on the enemy that you are fighting. If you are fighting a fire enemy, then Shiva will probabaly do about 9999 damage, but there is still that chance that she will do less. It all depends on luck.

You got to make Yuna really strong by fighting with her in battles.

Your aeons gain power based on how many sphere levels that you have gained with yuna. So if your aeon sucks, then you don't use yuna enough.

She should attack and do that much but check what Diamond Dust does, it should do 9999.