Let me explain the Lightning meme for you:
It's when the company/creator pushes this particular character so hard and rarely half of the fanbase likes that particular character
Lightning fits that role considering Toriyama (no, not that one) pushed her massively hard for her and Square shoved her in multiple titles and advertising and over favorable FF characters over her.
It's the same thought process for Rosalina considering people believe she's hogging the spotlight from Waluigi, Daisy and even Peach in certain cases when she's popular, Lucario in that light for Game Freak considering he was pushed hard for and he was considering hogging the spotlight (especially when he was Brawl and Mewtwo wasn't) and Lucina lastly due to the base breaker of FEA and people stupidly thought that she'll replace Marth as the face of FE when that's impossible and stupid to consider that.
Don't try to change it up or say I don't understand m, THIS IS WHAT THE LIGHTNING MEME IS:
This character is too popular and might attract the wrong people unlike my character
Some of the characters you gave as examples don't even really fit the bill, though.
The only hate I recall Lucario attracting was that of Mewtwo fans after Brawl's release when he was being used as a sort of scapegoat for Mewtwo's failure to return. Outside of that one isolated incident, Lucario has more or less become the most popular Pokemon outside of Generation 1.
Rosalina is by far the character I see get compared to Lightning the most, but it doesn't really make any sense. Rosalina made her debut in 2007, and it took until 2013 for her to really become a mainstay in the series. She made sporadic appearances between 2008 and 2012, but was only a playable character in Mario Kart titles. Rosalina was by no means forced into the spotlight like Lightning was. Her rise to prominence in 2013 was rather sudden, but I believe it was a result of the fanbase she actually built up, and wasn't the result of Nintendo wanting her to be a major face of the Mario series like Square Enix wanted to make Lightning be.
I won't comment on Lucina because I don't know much about who's popular and who isn't in Fire Emblem. I recall hearing Lucina is beloved in Japan, but at the same time, I recall hearing that Japanese gamers hate Roy, and that ended up just being a myth.
That isn't what the Lightning meme is, it's just when a character is forced down our throats despite lukewarm reception, nothing more.
Lightning has never appeared "over a favourable character", every game she has appeared in outside of the FFXIII series, has been a general FF crossover, like Dissidia. It's foolish to say she's being forced by appearing in games like this, since she is the main representative of FFXIII, so if they want to represent that game, they jump to her because she is the most well known character from the game, and has also proven to be popular in various polls and just the fact she was a legit role model in Japan (i.e. Japanese people looked up to her as a symbol of what they should be like). It's no different to how Cloud is the main representative of FFVII.
So the Lighting meme doesn't apply to Lightning herself.
Trying to say Lightning is forced by Toriyama is no different to saying Rosalina is forced by Koizumi. Neither are true and there were legitimate reasons for them appearing in more stuff.
Eh, I believe they really tried to make Lightning be a major face of the Final Fantasy series, but people do have the tendency to exaggerate the extent to which Square/Toriyama went in order to make it happen.
The "forced cameo" complaint in specific is beyond ridiculous. Other Final Fantasy titles and characters have gotten the same attention and treatment that Lightning and XIII got. XIII wasn't the first to have sequels. Lightning wasn't the first to make cameos outside her game.
Cloud was in pretty much every Square game released around the time of VII (He was a playable character in Ehrgeiz alongside a chunk of the FFVII cast, was recruitable in Final Fantasy Tactics, and was unlockable in Chocobo Racing alongside Squall). FFVII had three other games and a movie. X had a sequel centered around playing dressup with Yuna just like Lightning Returns. Nobody complains about their "overexposure".
People act like Square is biased towards Lightning, but it feels more like the fandom has a bit of bias against her.
The Hand Slap Down Special and the roll as a Dash Attack (when I saw that it changed to that I was legitimately hyped) are great though.
