"The Demon King's Castle has always been heavily guarded. However, that fool was recently goaded by the other Demon Kings into becoming a pawn for the Abyss. So, the castle is only defended by a few members of the Demon Race now," Edith explained to Su Xuan in detail. "But she might still be inside the castle."
"Who is this 'she' you're talking about?" Su Xuan asked.
"The previous Succubus Empress. She's quite a handful," Edith said, putting down her fruit juice. "Mary probably doesn't know that her former Empress is still alive, otherwise she never would have entrusted you with going to the Demon King's Castle."
"The Succubus Empress..." Su Xuan murmured under his breath. 'Even though the Succubus Race has declined, the power of their Empress still can't be underestimated.'
"It seems I'll have to accompany you on this trip myself," Edith decided. "As it happens, I also have a few things I'd like to discuss with her."
