Does the attack power have any effect with the symbol? Like...are dark attack more powerful than fire or it does the same damage but just different symbols?
Thanks, I really wanted to know the answer to this.

None of the seven attack icon types is more powerful than the other. However, some species have resistance to certain types of attack, or weaknesses against it, and of course many defensive weapons (shields, dual-duties, etc.) will block some types of icons but not others, but an icon of say water attack is the same power as an icon of earth attack, etc.
Oh i see. Alright, thanks a lot.