Talk:Underworld Tower to Heaven/@comment-3125054-20170809025052/@comment-27892764-20170809085731

Any boss with whom you begin an encounter amid Rune Time, will yield Rune Time rewards, from what I recall. Also, Rune Bosses always drop 1 - 2 Runes.

Though, don't leave the game on the  Screen after an encounter: this doesn't count for the external Time Stop spell. I defeated a normal FAW today, and left the OK screen on until BP had refilled some, in case of a Rune Witch. By chance, a Rune Witch did appear, but its time expired immediately, before I had a chance to fight it.