
heh, I feel special..
In half-life trailer (heh .. i know it's a typo made by you.. but it's not 'has-life' trailer

), what I did in that part is -
C
- A switch that ends the last scene
A
- Create 1 wraith owned by Player X at 'Gordan Freeman Center' (create unit)
- Center Location 'Player X Wraith Center' on Wraith owned by Player X (I usually center two locations and create units in the smaller location and kill units in the bigger location)
- Order all wraith owned by Player X at anywhere move to Location 'Wraith X move to'
- Set Switch 1 (set switch)
- Wait 3000 milliseconds. (this mite cause a wait block for the next trigger so make the next trigger owned by the player who have hyper triggers if you dont have the want the wait in the next trigger.)
- Set Switch 2.
Then another trigger
C
- Switch 1 is set
A
- Wait (not recommended, you could try using hyper triggers)

- Create 12 Scouts at 'Player X Wraith Center' for player 7 (or any other that isn't Player X,Y or Z)
- Kill all wraith at Player X wraith Center for Player 7. (or just Kill all wraith for player 7)
-Preserve Trigger.
Then do these two triggers respectively, for Player Y and Player Z using Switch 2,3,4.
Start the trigger for Player Y when Switch 2 and activate explosions using Switch 3. After ended, use Switch 4 to start explosions following the wraith owned by Player Z.
Start the trigger for Player Z when Switch 4 and activate explosions using Switch 3. Clear Switches 1,2,3,4 after to stop the explosions.
I didn't proof read .. a bit lazy today
