@zelink_for_life
I mean we have to think about all of their abilities too. Mipha's Grace can only be used once in a while, but I think that is because link is using it. I think that if the ability is passed down manually and not by, like, descendants (ahem-daruk) then it can be used at will. So, if I'm correct, then Daruk's Protection and Mipha's Grace would've saved their lives if they used it correctly. I might be wrong, though, because they DID end up well, dead.
I saw a theory video once that said something along the lines of this:
The Blights absorb the abilities of the Champions once they killed them.
I believe this because a) Link is able to attain these abilities once he defeats the Blight Ganons, b) In one of the phases of each Blight (2nd phase, I think) they use their respective Champion's abilities: Fireblight does the big barrier around himself and you have to use Remote Bombs, and Thunderblight infuses his weapons with electricity.
Sorry that was so long! I just needed to vent. I've wanted to talk about this for so long!