TL:DR at the bottom.
Imagine a map based in New Alexandria. The sun is setting, and 3 grey towers stand gravely. One of those towers is Club Errera, with 2 other towers in front. A crane links the two outside towers, and one bridge leads from the Club. Another torn bridge leads to the other tower. Falcons sit on the landing pads. A Pelican is parked on one of the towers,a mac gun on the other. Banshees, Phantoms, and Spirits terrorize the buildings, and a corvette hovers over the structures with a force field. Take the elevator down from the Club, and you enter a flat shopping center. There are dazzling fountains, snack bars, jewelry stores. Bodies. On one side lay the remains of a crumbled storage building by the water, and on the other, a parking lot. Here, civilian vehicles are parked. Streets form around the buildings, until you reach the force field where you must turn back.
You begin the match by either spawning, dropping in via drop pod, or dropped off by a pelican. As the game progresses, day turns to night and lights flash on. Skyline can be played in a number of ways and can be split into separate maps, or as a whole. One level takes place on the ground, another on the towers, and another inside the dance club, serving as a remake of Crater.
Those 3 spaces are used for normal firefight. As a whole, though, you can use Invasion. When playing Offense, starting off at the bottom, you work your way through enemy forces and climb up via stairs or elevator. Ending up at the club, you return outdoors and fly up to the overhead corvette. Boarding it, you bomb it, terminating the force field.
When playing defense as the Elites(or spartans, if you choose), you prevent the enemy from doing the above. For this gamemode, and every gamemode played on Skyline, you can choose to add AI allies, like Marines, ODSTs, Elite Zealots, even Gueta!
Phantoms would be drivable, and seraphs come in occasionally. Friendly reinforcements could bring a pelican full of marines, ODST’s dropping in, or Pelicans dropping in vehicles and weapons.
The civilian vehicles would include the ones from campaign, as well as several sports cars, motorcycles, and something similar to the H3:ODST police car.
TL:DR: Giant city firefight map with lots of vehicles, AI, and Invasion action.
Feel free to add on to the idea and suggest changes. Constructive Criticism is wanted. 343, MAKE THIS HAPPEN!