Instead of a obsessing over Jashi, can we just remember the fact that all the women who previously tried to seduce Jack inevitably betrayed him. This pretty much would leave Jack understandably hesitant to listen to his heart anymore.
Then he comes across a women who has been brainwashed to hate his guts and trained from birth to kill him… who eventually becomes a person who not only proves to be his equal in battle, but can trust her to watch his back in combat.
And not until after nearly dying while fighting alongside her, does he finally open his heart to another.
Her deserves this. Just let him be happy.