Just before anyone gets uptight about it, I’ve to say: I have absolutely nothing against accordionists, in fact I love the accordion. I just couldn’t think of another instrument other than harmonica that was both fairly portable and easily capable of multiple notes that are clashingly close together.

I love that you’ve portrayed the minor second with a slightly impish figure – it’s certainly a very chaotic, discordant and even slightly childish-feeling interval that fits this demonic little character ever so well.
At the same time, you retrospectively look at the actual stigma of the tritone itself very cleverly – and it’s true, the minor second is probably a more painful note to listen to, especially to the Mjr. who can clearly find a kind of beauty in the forbidden Chord.

As for accordion use, I certainly can’t see any issue with it – especially seeing as the Kalimba is the only other instrument I can think of that fulfils the requirements that you discussed.

Absolutely fantastic way to approach the challenge!

A bit convoluted for readers outside of the musician circle.