I've been giving the idea of Yugioh RPs some thought lately, and while you hit on a lot of good points, yugioh RPs (that aren't borderline tabletop RPs) and more broadly the anime tends to be an asspull contest. I'm not sure how you plan on handling things, but while shifting the focus of the RP towards a fantasy world of RPG-based monsters can help that aspect, it doesn't sound particularly conducive to player agency. Don't get me wrong; running an RP is difficult and running an RP well is impossible, but I have concerns about how much players will actually be able to make decisions if the world isn't robust enough to handle going off the rails.

There's also a lot of obvious mechanical questions, like how to avoid players solving every problem by busting out a Raigeki or solving every problem with their ace monster which just so happens to have non-targeting, non-destruction board wipes. Are we going full RPG monsters where effects barely matter, and if so, what do effects and spell/traps even do? Are we doing actual duels, and if so, what are the stakes when players are expected to style on every enemy?

Finally, I also tried to test out the deck sheet you made, and I'm not sure sticking to exactly 3 in each category or having arbitrary categories like "signature dragon" is ideal for giving people an idea of what the deck is like, how it works, or even the simple aesthetics of it. This might be because I filled it out with an actual (if slightly aged) non-archetypal deck, but I'm not sure it would work perfectly even with more thematic decks, other than rote archetype decks. Did you have custom cards in mind for this RP?

[hider=Level 1 Deck]Signature Humanoid Creature: Number 54: Lion Heart
3 Favourite Support Creatures:
[list][*]Kinka-Byo
[*]Treeborn Frog
[*]Battle Fader[/list]
Signature Dragon: Number 99: Utopic Dragon
3 Favourite Spells:
[list][*]One for One
[*]Where Arf Thou?
[*]Rank-Up-Magic Argent Chaos Force[/list]
3 Favourite Traps:
[list][*]Evenly Matched
[*]That's it
[*]There are no other traps worth mentioning[/list]
Any archetypes within the deck:
[list][*]4 Ghostricks (Lantern, Jackfrost, Specter and Dullahan)
[*]2 Numerons (Ekam and Sunya)
[*]2 Utopias (Roots and Utopic Dragon)
[*]1 Morphtronic (Vacuumen)
[*]1 Lyrilusc (Promenade Thrush)[/list]
Most Powerful Boss Monster: Number 99: Utopic Dragon[/hider]