Is there a place where enemies always spawn on a roof?
There are some places in the city where enemies always spawn. Some examples include in the tunnel under the prison, right in front of the hospital, or on the plane wing sticking out of the trash town.
Is there such a spawn point that happens to place the enemies on top of a building somewhere?
Note that I've finished the game, so spawn points due to missions are obsolete. All missions are complete.
Before you answer please remove all thoughts of stunts from your head. I want to know where enemies will ALWAYS spawn on a ROOF, regardless of your completion through the game. Nothing more, nothing less.
Solution 1:
Sevael Method:
This works even if you have completely cleared Neon.
Start by going up to Zeke's place. This will become your new respawn point.
Hop down onto the tracks just north of Zeke's building and head east on the rails. Right up ahead is a train station. Head down to the water just past the station. There is a broken dock in the water here with a blast shard way out on the furthest pillar. You can grab the shard at this point if you don't already have it.
All you need to do is to jump out onto the first pillar of the broken dock to trigger the upcoming Reaper spawn. Just glide out to the first pillar, then turn around and glide back onto land. You'll notice that when you turn around to face land again, a ton of people coming running up to meet Cole (if your Karma is Hero).
Head up the stairs to the train station up in front of you. As you run up those stairs, five Reapers spawn on the platforms in the train station. There will always be two on one side and three on the other, and which side gets three is random.
Get yourself over to the side with the three Reapers and kill the two on the other side to keep them from shooting at you. If you have the shield, now is a good time to use it. You can somewhat position the Reapers by moving towards or away from them. Get them into either stairwell, as this is your key choke point to hit all three with a Shockwave blast.
It's probably easiest to head down one of the stairways towards the street and wait near the bottom. The three Reapers will join you on the stairs and run back and forth while shooting at you. Keep your shield up and wait for all three to stand in the same position. Since you can't always see all three at once, just watch for the three red marks on your mini-map to clump up. Once that happens, immediately run up to them and use Shockwave. If you can keep your view pointed slighting upwards, this increases your odds.
If it went well, you will get the Have A Nice Fall stunt. If you failed, just jump into the water and you'll immediately respawn at Zeke's. Hop down to the tracks and head back to the train station and try again.
I've used this and it works. There are some possible quirks. Here is a link to an archived thread discussing this method: http://www.gamefaqs.com/boards/942025-infamous/49726407
Here is an embedded video to help visualize this method: