Yonder
Smashboard's 1st Sole Survivor
Honestly, I forgot Greninja. Yeah I can agree with 60:40, Amsa beating 2 strong Luigi players [Boss, J Miller] is further evidence of this too.@ Y Yonder I think you should add Greninja to the list of bad MUs for Luigi. Greninja outcamps him with a faster projectile with more range and forces Luigi to play his game, which already puts him in a bad spot. Greninja can bait cyclone as an approach option and punish the end lag of it with a grab. Luigi really can't escape Greninja once in a disadvantage thanks to his bad mobility, while the frog is a contender for best mobility in the game. Off-stage, it only takes a b-air to really mess with Luigi's recovery as well unless you're really good at mashing that cyclone.
On the plus side for Luigi, he can combo Greninja pretty well and N-Air can help him escape juggling, but even then it's really hard for Luigi to approach Greninja safely and start a combo when he can pretty much zone him out with shurikens. Cyclone is also beaten by fully charged shurikens so there's that too.
I think Greninja vs Luigi is 60:40 Greninja's favor since he pretty much forces Luigi to play his game all the time.
And I did say it was even or slight Luigi favor for Marth, Emblem. So if you said it's straight up incorrect, why would you list the same ratio as me? A bit contradictory. He's no where near as scary for Luigi in this game. I'd lean more towards even like you said, but that's only from like, the best Marths ever. Not easy, but not really hard either.