The newest use for magnesium is as an IV drip in severe asthma. I have never used it (partialy because my old dog brain can never remember that we can do this now), but every medic I know who has used it swears by it. I think if I had had this experience, I would likely list Magnesium higher.
An ED doctor told me once, Epi stops the reaction and Benadryl cleans it up. So while Benadryl is a great drug for allergic reactions, it is not the ultimate life-saver epi is….Still I would hate to not have Benadryl in my kit.