Ace adjective – Having or showing exceptional knowledge, experience, or skill in a field of endeavor. Capital and ace are semantically related in good topic. In some cases you can use "Capital" instead an adjective "Ace".
Ace Combat 6: Fires of Liberation also has a battle for a capital, but for your own capital, Gracemeria, which you liberate from the enemy's occupation after having to abandon it early in the game.
Witch with a Capital B: Brooke calls Melissa, who, by the way, does actually have magic powers, a witch here.Brooke: Ace, tell this witch you are too good for her.
The penultimate mission of Ace Combat 04: Shattered Skies follows the capture of the Erusean capital Farbanti, which (almost) ends the Usean Continental War.