This song is in the minor mode, which is typically associated with a spectrum of more "negative" emotions, ranging from sad and nostalgic to ominous, to "apocalyptic." The up-tempo pace, banging drums, over-the-top vocal delivery and dramatic orchestration all push this song towards the latter end of that spectrum.
However, in particular regards to the feel you're getting in the chorus, I do think the two note motif you mentioned plays a decisive role. It's a minor second, usually considered (along with the tritone) one of the most ominous and dissonant of all intervals. It's descending, which usually feels less hopeful than ascending. It emphasizes the minor third of its chord, which is the note that lends the scale its modality, and finally, it has a cadence that doesn't feel like a resolution (I believe this is i-V).