Season 1

While first reading your comment just now, I didn't quite recall how the season had ended, but—given what I'm now starting to remember via your comment— I'm figuring that perhaps the explanation you're in need of regards (more full) conception of the “stub”-related aspects/concepts (that, IIRC, might not have been explicated, and instead might have relied on trust in its audience's recognition of the show's alluded concepts/philosophies/scenarios/mechanisms)…

Consider the potential philosophy where one has no particular fear of death because, for THEM at least, nothing exists after death and thus there will never be any recognition or recall—much less regret or remorse or resentment—of ones OWN death (or the life course that preceded it) since they will no longer exist and can no longer [ANYTHING] (e.g., think, feel, register). In that case: the only possible consideration one would have would be for those that might survive them (i.e., those others that remain living after one's self has died).

Now consider either of the following respectively/mutually tantamount philosophies on a continuation (of events/~time): heaven (i.e., the instantaneous correction of everything to the optimum once once/after one dies), or an *omniverse/~multiverse/*pluriverse (i.e., infinite alternative courses of events / alternative realities — which implicitly includes the choice of the optimal course of events, the optimal reality, as well as all the other possible realities). In these cases: even possible consideration for what happens to everyone/everything other than one's self now vanishes too, since ANY reality could exist for them (as well as for one's self)(even including a reality in which you have not died). In this case, one's/ones death is as if it didn't occur, because in the alternative path it in fact does not occur.

Now, if I now try to remember specifics of the show, I think the dealie/situation was that… umm… someone was trying to profit from other realities and from their (quasi-possibly philosophically approvable) disregard for (i.e., lack of care over) those other realities (since they don't regard those as “the”/their reality, the reality that they believe they must suffer the negative consequences of, the one they think of their self as living within—just as a selfish person might decide to disregard their ruining of the planet if they think they won't be alive to live with the ruins—by psychologically “othering”/distancing/discounting the other realities from their consideration), and… uhh.. well, I don't really remember at the moment exactly what happens in the plot that you were alluding to with regards to “sacrifice” (since the exact plot won't matter to me again until the next season hopefully comes out for me to watch), but considering some of the thoughts elaborated above probably helps to address any confusion you have over it.