A startegy good for this battle is to change the weather. I heard typhlosion is good with eruption. Also bulky poison types are good for this fight like garbodor
I think graveler can work for some of this fight (which they are underneath the grand stairway) and numel not too good due to rain dance. Slugma also works well just be careful of the anorith and araquanid. (Its mostly just the rock moves)
I was looking through the Rejuvenation Folder and was in the pictures folder and found a picture called "FlorinExecution" and was curious what this was cause Ive played through the game and have never seen this scene
FlorinExecution.bmp