It was a superpower of hers (not for the purposes of the movies a mutant power, because at the time of her introduction into the MCU, mutants were verboten as they were part of the Fox X-Men license) and not magic. Strange’s, I tend to look upon as with D&D magic – it wasn’t replicable and nobody IRL is seriously trying to become a Sorceror Supreme, and no real supernatural entities were invoked – Agamotto ain’t real.
That one, I’d love to hear from someone more up on moral theology. It fit the “caper” and “time travel themes” so it didn’t bug me.
I’ve heard a lot from all over the map on this, but I tend to think that what both Natasha and later Tony were doing was at least somewhat cognate with something like Maximilian Kolbe willingly allowing himself to be starved to death to save another who was marked for that punishment. Giving their life so others might live.
I doubt the Church has any sort of view on it either way – nobody has been able to do it in real life (that we know of).
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