Astral Heats can only be used on the final round of each match when a character has 100 percent heat meter. This meter is built by attacking the foe, or by pressing R1 against the AI. Even if you're hit, the meter will have already filled to it's maximum capacity. If using a second controller, simply force instant blocks with your first controller (perfectly timed blocks, the character flashes and takes no damage) and build your meter up.
In order to execute the Astral Heats, you can either refer to the command list or simply choose beginner mode. When playing in beginner mode, you can press Square, Triangle and Circle all at the same time and hold them in order to instantly initiate an Astral Heat. Some characters have certain conditions, such as Litchi must be on her staff and Lambda has to be withing grabbing range of the opponent.
After doing your first Astral Heat in either versus or Arcade,this trophy shall be yours!