Sorry, man lol
Where it's alike
-Harem-type
-Strong male lead
-References (In Aria, it's historical. In Campione, it's mythological.)
-Fights
Where it's different
-No extreme tsundere for Campione (there are a few moments, but not Aria-like)
-Male lead can activate his powers more easily in Campione
-No important cliffhangers at the end of the volumes
-More 'powers'; by that, I mean different types of attacks
-More awesomeness when a character starts his/her attack
Basically, that's it.