The Twin action is broken into three parts:

• The player chooses the “Twin” command on character (A)
• Twin is queued on that character, with a delay of 0
• When the pointer comes back around to that character, “Twin” executes:
  1. Their partner (B) is chosen
     • In FF4FE, if there is more than one potential partner, they are chosen at random from the available twins¹⁾
     • If there are no other twins who are able to cast, Twin fails
  2. The “TwinCast” command is queued on both twins, with a delay equal to character (A)'s relative agility divided by 2²⁾
     • The same Action Timer delay is used for both twins

• If the partner already had a command queued, it is replaced with this
• TwinCast will execute when the pointer reaches one of the partnered twins and their delay timer has expired
  • Which twin this will be is highly dependent on the ATB situation
  • Since both twins have the same timer, if they are in consecutive slots, the twin in the earlier slot will (almost?) always be the one to execute TwinCast
• Both twins will start a casting animation
• The twin who executes TwinCast will queue either Flare (75%) or Comet (25%)³⁾. This twin's Wisdom stat will be used to calculate damage
• Their partner will simply get a Wait command

• Works like a normal spell cast at this point, queued and executed by the twin who executed TwinCast, and using their Wisdom stat for damage