Kahn faced Axel with eyes full of hatred and disdain after the latter told him about what he'll do to Venessa after killing Kahn. But the current situation was very dire for him at the same time.
His identity as Hero of Darkness was exposed and there was a chosen Hero as a witness on top of it. Even if Venessa chose to side with Kahn and they somehow managed to leave this isolation barrier… Axel would inform the church and soon, the entire empire would be after him.
The church could also use this news in their favor saying that the princess is allying with the hero of darkness and thus, their crusade against the imperial rule is righteous.
On the other hand, Kahn thought of Venessa as a friend at this point and after seeing how she tried to let him escape even by risking her life while fighting against the Hero's party by herself… he already held her in high regard.
"Kill him!"
