Sachant qu'il n'y a pas de if , il ne peut donc pas y avoir de else , l'erreur vient de là.
Et aussi , je te conseille d'utiliser le "hide player to players" , au moins il n'y aura pas de particules.
command /vanish:
trigger:
hide player to players
spawn 10 bats
strike lightning at the player
strike lightning at the player
strike lightning at the player
strike lightning at the player
strike lightning at the player
strike lightning at the player
strike lightning at the player
wait 15 ticks
kill all bats
set {vanish.%player%} to true
if {vanish.%player%} is false:
reveal player to players