Let This Grieving Soul Retire, Vol. 5 (manga): Woe Is the Weakling Who Leads the Strongest Party — Tsukikage

As Krai and the First Steps prepare to raid the White Wolf's Den, Sitri Smart, creator of the monster slime on the loose, shows up just in time! If anyone knows how to deal with the missing slime fiasco, it's her -- except she also has no ideas about its whereabouts or what form it may have taken. Instead, she has more bad news: The threat in the vault is something entirely different and way more dangerous…Just what kind of trouble did Krai send his clan into?