I'd absolutely love it if you would be more detailed in what you mean that marth takes the cake.
I doubt that he wins every aspect. Match-Ups are done in 50:50. I won't be convinced until it's been studied.
Well, Lucina and Marth have to play basically exactly the same. Marth's attacks are far safer than Lucinas, and he has slightly more vertical range. Like, pixels of difference. Which makes all the difference when you live in tipper land. His tipper attacks all do loads more damage than Lucinas, and he can kill ridiculously earlier than her.
Like, no rage, Marth needs about 70-80 percent for an easy kill. Lucina needs to be between 110-120. I always lean twoards the higher numbers due to DI when it comes to Lucina, and lower numbers when it comes to Marth because tipper hits also add more hitstun/hitlag, and have much more KB.
This leads to Marth being able to live insanely long (seriously, like up to the 200's. Rage stops bulding after 150%, I believe) and Lucina dying before she can even get him that high. It normally takes her 2 stocks to get into kill range against me, so barring a
*great* gimp or an SD, I'm keeping my stocks for much longer than she is. She really
REALLY has to outplay me to get that first stock before I get hers.
Let me tell you something though, Marth with Rage is probably scarier than the best of Shieks. He can kill at insanely low percents. I've gotten kills around 20% (either at 20% or slightly above it, less than 25%) on ledge before with tipper FSmash. He can get a kill with Upthrow if Lucina is high enough. This is all assuming Lucina and Marth are playing at the same level of skill. I've played some good Lucina's who have outsmarted me, or atleast taken a set or two off of me. However, I've played many more Lucina's at the same skill level or below. And they lost all the sets I played against them.
Lucina is going to be searching for a kill for a while. Likely long after her first stock is gone. Marth however, is going to be able to stay alive pretty easy. If he's been playing smart, he won't be in Lucina's kill range for atleast another half a minute. Lucina, playing at the same level, is going to be struggling to get him up high, and will likely be in his kill range without rage before she can get his stock. This means that even if Marth loses his stock, Lucina is liable to bite it at the first well placed tipper attack near the ledge. It is a hard MU for her. Probably one of her hardest, because even though sheer character data suggests that she should be able to do mildly okay against him if she tries hard, she really really has to outplay Marth to beat him.
Those are my thoughts on the MU. Most of them anyway. I trimmed the fat a little bit, I could have gotten into more Rage Marth situations, which limit Lucina even more and make her respect Marth about twice as much, but that is the real nitty gritty of things.
I know how Match-ups are reported. This isnt an MU thread, however. There is one
here . What that lovely discussion found is an indefinite 40:60 in Marth's favor, until further notice due to how customs could affect the MU. Based on personal experience, I'd say it'd be more like 20:80 or 30:70 in Marth's favor. Lucina mains have to try a lot harder to beat Marth mains. Marth mains have a pretty easy time against them. Their only decent option against Marth is to try to get in his guard and be real aggressive, but that is a terrible idea against Marth and will get you killed.