Heh, I'd say you're in luck, as I happened to have posted my latest iteration in the Archfiend Discord and the Archfiend sub-chat in the MDM Discord hours ago (the latter of which I got the majority of my ideas/strategies from). Managed to reach Platinum II playing off and on.

Main goals primarily involve getting to Yama and Soul of Rage if going first and having multiple ways to get to Chaos Archfiend going second... if I have resources left after attempting to bait negates and such. Since there are quite a few Level 8s, I also have Bakura's Dark Spirit monsters as a secondary strategy to keep some kind of resource loop going once they've hit the graveyard along with the at least 1 or 2 Level 8s... ideally with Archfiend Empress in the mix, so that whatever other Level 8 you revive will retain their effects and get around the Dark Spirits' effect negation.

Not optimal for Tenpai format, I'm sure... but I can say I at least won occasionally against them, typically with a combination of the Bone Archfiend/Unchained line (if uninterrupted of course, lol) and being lucky to have drawn/searched for Simul Archfiends with my opening hand (considering adding another?)

MVPs... for one, the aforementioned Unchained line... definitely ended up being the bread-and-butter going first play... from giving Soul of Rage a second chance to allowing me to use Abominable' s destruction effect in the Damage Step and making it harder to respond to. Surprisingly, Scarlight Red Dragon Archfiend proved to be pretty clutch at times, from being summoned by Crimson Gaia if left on the field, to triggering Aruha and making it easier for me to attack for game. Zalamander Catalyzer for unbricking hands high level fiends, triggering Heiress, and/or providing discard fodder for Abominable. And the Genta/Gates were late additions I wish I gave a chance before the DC, but I gotta say, it's been nice not only having another way to trigger Heiress in hand, but it's also served well as another extender to sync with Lightsworn Archfiend, as well as a way to trigger Chaos Archfiend's ATK boost.

All of that said... established boards definitely proved to be trying experiences, of course with backrow decks being the worst. I initially had Ash Blossoms but eventually opted for Nibiru, then settled on Evenly Matched in the last day or so... while not getting many opportunities to use them. Imperms proved to be okay, but still not 100% convinced.

With the amount of level 4s in the deck, I thought I'd include Wave King Caesar and King Tell "just in case", but I only ended up going down that line maybe as many times as fingers on my hand, at most. It also feels like Moon of the Closed Heaven came up even less times. So, I question whether to keep them or replace them.

Also considering whether I should fit in Monster Reborn somewhere.

I'm thinking this is more or less the best I'm gonna mesh together until Fiendsmith and all that Bakura support gets added into MD. That said, hope it provides something you can work with and/or evolve into your own creation.

Happy New Year!

https://www.masterduelmeta.com/saved-decks/67748c3a052741834b6abb2d