I watched the Vudu set. I like that you got a lot more patient as the games went on. Like, in the first round, you'd set up a desynch and quickly approach with something like a full jump Nanapult, which is not safe against Luigi (short hop Nanapult is way better). You still would occasionally take pointless risks or let Luigi squeeze in through your walls in weird ways, but I'm guessing this is due to MU inexperience more than anything else (or at least experience in camping Luigi). Probably the biggest way Luigi tends to get around walls is by approaching from above when he's at a low percentage. He can eat a rising Popo uair and then nair you at really low percentages, so you need to watch out for that then. When he's at 30%-ish or something like that, you should still watch out for nair, although I think around this time you should be able to avoid it pretty consistently by either fastfalling (if the uair hits near the peak of the jump) quickly or by drifting to the side.
Minor nitpick #2: You don't deal with Luigi well when he's above you. Like, when he approaches you from a platform, you often retreat to the side or try to intercept him with usmash. Usmash is risky because of its long-ish start-up, and it doesn't tend to lead to much. Retreating isn't bad per se, but you can do considerably better things. The big option I never saw you use is utilt. It really cleanly beats most things Luigi can do from above; it'll lose to well-spaced dairs, but it's not very hard to judge whether he's in a position to do those. There were a lot of times when you were standing next to a platform when Vudu tried to quickly approach you from above, and you could have cleanly beaten that by just standing in place and throwing out utilt at the right time.
Back to blizzard-camping (My post-formatting has gotten lazy and weird in my current post-academic-year condition): It feels dumb, but when you have a lead, it's often best to just sit there and keep shooting ice blocks and blizzards. Even later in the set, you'd sometimes make a weird gamble when you could just sit there and keep up the wall. It can be boring or stressful to just sit there and not mix it up at all, and I think the simplicity of the inputs you're entering adds to this, but recognizing that Luigi needs to make big gambles to get around this sort of wall most of the time (at least when you have the lead) is important if you want to play the match-up in this sort of slow way, which is also how I like to play it.
