A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 5 November 2011
Does the performing spirit in the constraints block of Rage of the Spirits have to be a personality or follower? Could it be, say, the spirit weapon created by Phantom Blade Kata?
Rage of the Spirits Battle: Even if this unit is not at the current battlefield, bow this Shugenja and your performing Spirit, and target an enemy card without attachments and with Force lower than or equal to your Spirit's: Destroy the enemy card. If this Shugenja is Earth, gain 1 Honor.
Phantom Blade Kata Limited: Put this card into play in your home. Discard any other Kata cards you control. While this card is in play, you have the ability, "Spirit Limited: Discard a card: Create a +2F Spirit • Weapon Item and attach it to your target Personality."
Brook Cunningham (rules official), 5 November 2011
Does the performing spirit in the constraints block of Rage of the Spirits have to be a personality or follower? Could it be, say, the spirit weapon created by Phantom Blade Kata?
Rage of the Spirits Battle: Even if this unit is not at the current battlefield, bow this Shugenja and your performing Spirit, and target an enemy card without attachments and with Force lower than or equal to your Spirit's: Destroy the enemy card. If this Shugenja is Earth, gain 1 Honor.
Phantom Blade Kata Limited: Put this card into play in your home. Discard any other Kata cards you control. While this card is in play, you have the ability, "Spirit Limited: Discard a card: Create a +2F Spirit • Weapon Item and attach it to your target Personality."
Only Personalities and Followers "perform" actions, so you could not choose a card type other than those two.
But since it doesn't specify which, you could choose either a Personality or Follower Spirit.