In such a dire situation with enemies on all sides, encountering a player specifically here to kill red-named ones is undoubtedly a natural ally for Captain Da Fei, not to mention that he's a masterful ally. So, Da Fei decided to return the Silencer's Dagger, the part of the set he blew up last time.
Da Fei certainly knows that missing a single part of a set will prevent the most crucial and powerful ultimate special skill from being activated, which would drive anyone crazy. So, he decided to make it easy for him, instead of driving him insane.
Blood Slaughter wasn't fussy and couldn't help but be pleased: "Weren't you saying you wouldn't return it?"
