As promised, here's my live commentary video detailing the "Mario Paint" strategy against Shadow Queen. This strategy is definitely the most optimal strategy for a Level Zero run, but don't think it's easy because of it. This boss is still super-hard. If you need more of a buffer because you're not comfortable superguarding, go for more Boo's Sheets. If you're worried about her healing, bring an extra Trial Stew.
Shout out to Koop, another YouTuber that I worked with when I first put my original video out to come up with this strategy in the first place. I just optimized it.
Paper Mario: The Thousand-Year Door Statistics For Kappy
Kappy presently has 1,110,634 views for Paper Mario: The Thousand-Year Door across 642 videos, and over 18 days worth of watchable video for Paper Mario: The Thousand-Year Door published on his channel. This is 29.10% of the total watchable video on Kappy's YouTube channel.