I was interested in running this game but my vision was to use user decks but from a new save file so I’d have to build my deck throughout the run. It doesn’t look like that’s a thing though, has anyone ever tried it? Would people be interested in trying it?

There was somebody, who had that idea a couple of years ago, but it has never been attempted in the end. The game has been very inactive for years, so there isn't really any demand to justify adding something new. Categories aren't just getting added based on new ideas in general. There have been other ideas for new categories in the past. If all those got added we would have an abundance of categories, which all would have been run by probably just the person suggesting it and nobody else. So unless there is a sudden resurge of players, that would all be interested in running the game that way and also doing so, don't expect there to be a leaderboard for it any time soon. But that shouldn't stop you from running the game that way, if you have interest in doing so. A game doesn't need an official leaderboard in order to be speedrun in some other way. I have done speedruns, that had no official leaderboard, myself like DM Battle Pack Draft.

Thank you for the response. I did some routing and on my first attempt managed to beat all of the first campaign including the reverse duels in just under 4 hours. Originally when I thought of running this I wanted to do the whole game but I don’t think I have the endurance for that lol, will have to see if the other campaigns end up being quicker due to already having a deck built up from the first one. I’m not very familiar with the later campaigns but I imagine they’ll be harder, especially Vrains

In terms of difficulty Vrains is a whole different beast to tame, especially with Story Decks. I assume it is not going to be that bad with a custom deck once you have experience with the campaign. My original idea for a new save file run back then, was to just lose to the the first duel after the tutorial in Vrains a bunch of times by just instantly surrendering the duel to obtain the cards for the Gouki deck, but I never tested it, so I don't know how good that idea actually is. I also want to mention, that because this is not an official category, you are allowed to make up your own rules. So for example, if you say the run is too long and too exhausting in one sitting, you can allow breaks. Just pause and save the timer, and then continue the run on the next day or so. I would suggest to do that after you finish a campaign though and not in the middle of one. You can also make a decision about whether campaigns need to be played in order and if you are allowed to use banned cards or not. Another thing I would advice you to keep is the definition for Any% and 100%. In Any% only the regular duel are required, while 100% also requires the Reverse Duels.

My plan was to do them in order and without banned cards, which I know doesn’t help with the length of the run but that just makes the most sense to me. Banned cards could go either way tbh but I get bored of playing Pot of Greed and Graceful Charity in every deck, and surrender farming a complete deck from the strongest campaign immediately and then playing the entire game without changing it up at all kind of defeats the point imo

The deck I used to get through the first campaign was an earth zombie beatdown deck. I started by modifying the starter deck and playing until I unlocked the Bakura pack, then spending all my point opening Bakura packs for Seven Tools of the Bandit and better normal summonable monsters. Then I kept going forward with the campaign until I reached the duel between Mai and Tea where I surrender farmed for points, Mage Power and United we Stand. Once I had those I opened a mix of Bakura and Grandpa Muto packs, looking for: Zombino, Zombina, Pyramid Turtle, Bone Crusher, Mezuki and Gozuki from Bakura, and Giant Rat, Milus Radiant, Missus Radiant and Gaia Power from Grandpa Muto. Eventually ending up with this deck

It worked out pretty well as it’s really simple to play and can deal lots of damage, and I’m pretty sure it could keep that momentum at least all the way through GX. After the game gets too hard for that deck to win quickly, I was planning on going back into the Bakura pack to build a Zombie Word deck. Zombie World and Doomking Balerdroch are both ultra rare but I should have plenty of points by then and I’ve already been in that pack so chances are I’ll have a lot of the stuff I need already. I haven’t had the chance to play since that last session though so maybe something else would be better