People have been talking about this for a little while now, I did arena_sacrifice which is sort of similar so now it's now a prefab.

• The point locks for 10 seconds after capping (alter the cap_lock relay delays for this timing_
• The team that just captured is given a marked for death debuff that lasts for 2 seconds after stepping off the point (modify the central add_cond for that's timing (make sure the debuff timer's refire is LESS than the debuff duration!))
• Each player us Ubered for 3 seconds upon respawning (edit the add_cond around the players for that)
• The respawnroom skins into the ground after 10 seconds, that's what the nodraw door is for. This prevents players changing class after the round starts.
• The small trigger brushes high up are vital to the gamemode, leave them be.
• The three trigger brushes that fill my dev-cube prefab map are vital to the gamemode, they must cover 100% of your play area. If a player leaves this area they're considered dead.

This is only a basic prefab to get you started, it doesn't have all of the anrea_resupply features, there are no firstblood crits and there are no last-man-standing crtis either.