YOU SAID:

Activity is compulsory in a Guild War especially during prelims, unless members provided reasons has prior to events.

INTO JAPANESE

メンバーがイベント前に理由がない限り、活動は特に中 prelims、ギルド戦争で義務付けられています。

BACK INTO ENGLISH

Members prior to the event unless you have reason, are especially in the prelims, Guild Wars mandated activities.