Given that one of the people with an orb is the ruler of Taeum I don't think the deaths would stop at two if we went down that path. We'd be assassinating a major figure and then leaving the inhabitants to pick up the pieces- and they'd probably declare war on Sedorum after we left, anyway.

Or there could be just one death. Entr'i's a good person, who wants to change this world so that instead of Taeum having everything, and Sedorum having nothing, there will be one realm, where everyone shares. And unlike the people in charge of Taeum and Sedorum, I've never seen her do anything but try to ease people's suffering. If she's able to assassinate the Highest One before the war starts and merge the worlds before then, there will be nothing to fight over.

And it's what most people in Sedorum want, anyway.