If I have a pidgeot who's cp is 450 and a pidgeot who's cp is 100, and both have the attack Arial ace (which deals out 25 damage), does that number ever increase the higher the cp? Or no matter what level the pokemon is on does it stay the same? Will it always just deal out just 25 damage despite how strong the pokemon is?
For sure, the number never changes
Other than that, there's still a lot of speculation going around, but for what I saw most recently on reddit and my experience, the damage dealt by an attack only depends on the attack power and the CP of the defending pokemon. It doesn't seem to depend on the attacking pokemon CP.
Edit : mons indeed have an attack stat, probably used somewhere.
To the history board:
In all Pokémon games there was an attack value (as well as an accuracy value) for each attack. This number never changes.
Does this mean the attack always deals the same damage? No!
The attack value is but one part of the calculation.
Another part of that calculation is the attack power of the Pokémon, which indeed grows as you level up.
This stat is rumoured to exist in Pokémon Go as well.
Will it always just deal out just 25 damage despite how strong the pokemon is?
No, but the base damage value of Aerial Ace will always be 25