I wonder if the poison on the knife was intended to have a certain...effect...on Taichi, to perhaps make him more violent or impulsive? He's certainly shown no sign up until now that he has enough of a temper/suppressed rage to kill someone in a situation like this.
thanks for the TL, and for bringing this one back!
When being summoned to another world that are rife with wars and the setting is medieval era, you'd best be advised to leave your pacifism self behind.