I think adverse just means "not good" as one could also see neutral or even positive effects; one would say severe or serious (as in the text you quoted) as str

I think adverse just means "not good" as one could also see neutral or even positive effects; one would say severe or serious (as in the text you quoted) as strength modifiers if applicable, but the word "adverse" shouldn't inherently make something sound strong or ever feel synonymous with "serious".