【とある魔術の禁書目録 幻想収束】The introduction of the article is unnecessary. It jumps right into the announcement of a limited Halloween gacha event in the game “Toaru Majutsu no Index: Gensou Shuusoku.” The event features the return of past Halloween-themed characters and costumes. Players have the chance to obtain these limited characters through the gacha. Additionally, there is a medal exchange system where players can trade in medals for other limited characters from previous Halloween gacha events. Overall, it seems like an exciting event for players of the game.