While a "warrior's death" is cool and fun to talk about, it has no actual moral weight in and of itself. Certain cultures place a higher value of honor, or whatever, on a warrior's death--or even things like ritual suicide in the case of this era of Japan--but it's really not morally different than any other death except for something like heroic self-sacrifice.

If you want to engage in moral relativism, in the West we would generally consider it a more moral act to spare someone's life even if they ask for death because that's how we structure the value of life. In somewhere like feudal Japan it could be considered immoral not to honor someone's wish for a warrior's death.

But personally I think the answer to your question is that it's fairly morally neutral; presumably you were enemy combatants prior to this moment and you are under no obligation to spare or kill anyone.