Board Thread:Questions and Answers/@comment-26383823-20150707155059/@comment-1419424-20150707160630

The Oracle Sword is one of my FAVORITE weapons in all of GE. It's somewhat obsolete in RB due to the skill install system, but what it does is drastically increase your Oracle intake capabilities through melee attacks and devouring as well as your gun attack power.

As for the materials, the Oracle Lightning Stone (オラクル雷石) can be obtained from high-ranking spark Vajratails and spark Fallen Zygotes, as well as from the following missions:

難易度7★歪なる複眼

難易度8★虚像

難易度8★ムーン・ソング

難易度9★遠雷

難易度9★眠れる獅子

高難度9★エデンの園

高難度9★皇帝の進軍

高難度10★明王の昼餉

The Philosopher's Stone (哲学者の石) can be obtained from the following missions:

難易度10★ブラックウォール

高難度9★廃墟の女王