Cool song. I didn't dig it as much on first listen as I did after a few passes. But maybe it started to stale slightly after a ton of listens. (That part of judging sucks, btw.) That's probably my fault more than yours.
Challengewise: I don't hear a downward modulation. In fact it sounds like your bridge is almost a modulation up. Then I read your liner notes. So I went to a music dictionary and looked up the definition. "1.The process of changing from one key to another." or "2. In electronic music, the term is applied to a change of frequency, amplitude, or other changes of similar nature possible through electronics." That second definition never occurred to me. You mentioned four points for your modulation. Low Pass Filter which satisfies definition 2. Tempo which doesn't automatically satisfy definition 2 but could and I think it's a cool interpretation so good for me. Vocal melody using a downward arc (not sure your phrasing) which does not satisfy either definition and a downward chord progression which also does not satisfy either definition.
All that being said. I do like your song. I ranked it a bit lower because I didn't feel it embraced the challenge as well as some others, but I still think it's cool.

For the second week in a row, your take on the challenge has puzzled me. You've "modulated" downward in several different ways, none of which lines up with what the judges had in mind when we deliberated the challenge. And I'm sympathetic to the fact that you guys can't read our minds, but the most obvious change-up that I thought was added in to address the challenge - the tempo change in the bridge - is not a modulation. Later, I looked at your liner notes to confirm. I guess maybe the filter thing technically meets the challenge? I don't know; you obviously put the effort in, even if I don't agree with your working definition of "modulation." But then it comes down to... What's the point of the modulation in this song? Does the gradual downward filter symbolize some aspect of the relationship between your song's narrator and his roommate/partner? You could argue that the relationship is getting darker and darker as it goes (and, jeeze, I've lived that, and I have the filthy sink photos to prove it!), but I don't think that interpretation stands up to scrutiny, because the narrator is already fed up and wants out by the end of the eighth line. I do like the chorus hook, and the "na na na"s are nice. I like the lines "If you really want to hate someone / You have to love them first." But I wasn't fond of the blunt "I think that you're the worst" that sets up the rhyme. Later on in the song, the lyrics become a banal list of complaints about household tasks, and that was where you lost me. It's not inherently invalid to sing about frustrations with household stuff, and I've been encouraging comeptitors to be specific with their lyrics, but I think at that point to me it just felt like the song was piling on, to the point of meanness, and it stopped working for me altogether at that point. I was really glad to hear more from Evermind this year, and I hope to keep hearing more from you (both!) in the regular fights!

this is really solid but for some reason never connected with me as much as most of your other songs this Nur Ein. Trying to put my finger on it, I feel like the chorus could use more of an anthemic lift - the melody is good but dynamically it doesn't really seem to kick in at that point as much as I'd like. I think it might actually be interesting if some of the instrumentation cut out at the start of the chorus and then crashed back in.