Here is what I had in mind for the map:
Birds Eye View
The coloured rectangles represent the warp in zones for each team. The coloured circles represent the location for each teams' crystal.
The black lines located near the warp in zones will act as a border similar to those used in the ToH mass battle between rounds. If a character has died recently, they will be warped back to their warp in point and will have to wait 20-30 seconds before they can continue. If they try to walk past those lines before the time is up, they will be warped to the warp in again. Once the timer is up they are free to continue.
Different views:
Top View
Isometric View
I could add a few more models to make the map a little more interesting.