"BLACK TAR" ExplanationA musical meme among image boards for the song in question being well received... up until the vocals kick in. See Broken Base.
WE'RE STUCK ON A DIFFERENT PLANETExplanationThe lyrics for one portion of the Skell version song, juxtaposed on a parody video on YouTube. Many of the lyrics for the song are quotable in their own right due to how ridiculous it all is.
"Man, this soundtrack sucks." *20 hours later.* "Huh, maybe it's not so bad..." *50 hours later.* "I CAN'T HEAR YOU! I CAN'T SEE YOU!" ExplanationA lot of players initially disliked the parts of the soundtrack that had lyrics, especially the NLA theme and "Black Tar" above. The ones who stuck it out often had the songs grow on them to the point where, by the end of the game, they were singing along.
"Asscaves", a highly quotable word thanks to one of L's remarks about the Ganglion.
"It's a horse eat horse world out there." Also from L's attempts to use human slang and expressions.
"L + A", the way how to favorite Free Report posts.
I miss Riki.ExplanationAnytime Tatsu does anything lackluster, chances are that someone will mention how Riki was better.
While this is also prevalent in other Nintendo games and others like it, a common meme on Tumblr is taking a screenshot of a hilarious dialogue choices. Some notable examples is the one that says that they are dead inside, and the one who mocks by playing the World's Smallest Violin.
Due to how Free Reports are shown in-game (displaying the ones with the most "yeahs" on Miiverse) the following have become memes due to the reports flashing on players' screens almost endlessly since the game launched, occasionally causing discussions of the game to devolve into just quoting the constantly recurring Free Reports.
YOU CAN PLAY AS OTHER CHARACTERS!?ExplanationThe whole prospect of switching into characters who aren't Rook seems to surprise people, who didn't think it was possible, when mentioned. This goes to show how this little feature was never mentioned in the entire game and how the manual was ignored.
Elma has◊ been◊ comparedto◊ Elmo due to their similar name and their red appearances.
"Elma Person\Elma People" ExplanationA common fanmade term describing Elma fans, based on her 2nd Heart-to-Heart, where she asks Cross if you're a cat or dog person. Naturally, knowing the game's choice system, you can claim to be an "Elma-person", with very much hilarious results.
The Superior Form holofigure is very memetic, for having H.B. pose in a Shirtless Scene.
This damn weather. Somebody fix this! ExplanationOne of Lao's soul voices. Jokes abound about the weather being responsible for every misery that befalls Lao, as well as the concept of "fixing" weather in the first place.
"It's this planet. It's something about this planet!" Explanation and spoilersThe quote is from the end of the story where Elma finds the Lifehold Core database destroyed on impact, and wondering how the mims in NLA are still active, often used to describe any Ass Pull in the storyline.
Elma's legs. ExplanationA number of fans on Tumblr have a rather odd fascination with Photoshopping Elma's legwear from her official render onto other characters or putting them into unusual situations. They're sometimes treated as a separate entity than Elma herself.
"Will I ever stop excelling?" ExplanationA Level-up quote from H.B that caught on quite fast, due to its sheer memorability and the fact that, well, you hear it every-time when he levels up.
The X stands for 10.ExplanationA half-joking theory based on the Roman numeral value of X that this game was secretly intended to be the 10th game in a grand Myth Arc started by the first game, due to a late-game plot twist in Xenoblade Chronicles 2 that had massive Arc Welding implications, and later Xenoblade Chronicles 3 being a successor to both games while also having some plot elements that heavily parallel X and hint at a possible distant plot connection.