Phoenix is a standard plug-in that is shipped with the BZFlag Source code. It modifies the starting, or Spawning position of a player tank so it will respawn where it last died. If the tank has not died ( first spawn ) the normal spawning rules for the server will be used.
Phoenix is not a plug-in for all server types. It is intended for race type maps where the goal is to finish a course, and weapon use is just to slow your opponents down. Phoenix should not be used on maps that have physics drivers that use the DEATH option, as tanks will respawn and just die again.
On a flag capture event, everyone will be reset back to normal spawns for there next spawn.
Phoenix was made in response to postings on the BZBB forums about the desire for a non-lethal weapon that disabled a tank for a short time. By respawning where the user was when they died, they are effectively disabled for a death time.