People's "unique" card can be changed at key points within the RP as sort of upgrades, so that decks don't remain stagnant or focused on static card types.
I feel the need to isolate this specifically because you don't seem to quite
get it
What you're probably referring to is a deck's "ace", the cornerstone that carries you through duels. Yes, these "change" in the anime, but only in so far that it's the same monster getting a new form. Atem's cornerstone is always Dark Magician, Judai always summoning Flame wingman Neos, Yusei always falls back on Stardust, Yuma plays Number 39: Utopia every duel, Yuya keeps going back to Odd-Eyes and Yusaku-
...uh
So anyway, while I was never really intent on having people specifically denote an ace in their deck, I don't think I'm going to be too fond of people who treat it like how you describe it to be. Besides, if a "unique" card can be swapped out at any point, I don't think it's quite so unique. Yeah, Jonouchi lost his Red-Eyes for a while, and he most certainly didn't start out with it, but his entire arc was still about him being becoming worthy to get it back. Red-Eyes never really stopped being his most powerful, most treasured monster, even when he didn't have it for a long while. Once you settle on your character having an ace, I don't think you should swap it out at all.
And back when I said "unique" I do mean it like that- unique. A one-of-a-kind card nobody else holds or is able to hold that pretty much defines your character's identity. It's not something that should be swapped out at will. Though it looks more likely, to me, that I will introduce some card or series of cards that are one-of-a-kind. The players can or cannot obtain it, depends on my mood really, and they don't have to automatically become what defines them. Despite Atem holding the three gods, his deck never stopped having its own identity. Hell, pretty much the first thing he did in his final duel, despite holding the gods, was turbo out his trusty Dark Magician. That should show how I intend that selfsame element to be treated.
Anyway, on card progression: I'm going to be real here? The more this is being discussed, the more I kind of want to eat my words as it's starting to sound like a bad and uncomfortable idea for me. If the people want it, I'm not one to deny them, but uh... I'm not going to lie, the whole "buying packs" aspect in Duel Tower was always kind of something that weirded me out and took me out of the story. Yes, it was entirely natural for these kids to go to ye ol' card shoppe and get some new stuff, but for some reason it always felt like an incredible detour. Having them also trade among themselves was a thing that happened, and looking back on it I just never... felt quite right with it.
The only time opening packs ever really came up was a couple of times in Duel Monsters, once in GX and then never again. I actually end up preferring when they don't go out of their way to explain where these cards come from, because despite the added realism, it just feels a little too "real" on my end. I'm just a weird guy though, so don't take my word for it.
Also I'm not entirely too sure about the card list idea; honestly, if people want new cards, 's prolly best just to tell me straight-up. Start of with a low-power deck that you upgrade over the course of the RP independent of any kind of system, but more just as your character grows. Think about it this way: Its pretty much been established that none of the duels are left up to luck at this point. Even if you don't write a skeleton ahead of time, the winner is more often than not predetermined, and even if it isn't, you can choose what you have at any given point in time anyway. Only one guy vouched for having me draw the cards for you guys, while the rest was like "nah we got this fam" so at that point I'm a bit "eh" about the whole card progression thing. I still think it should happen, but not something that should be given too much attention or focus. More like... just updating the deck as you go along. Swap out cards you don't use, maybe streamline it a bit but still have the identity you started with.
It's just my personal take on the situation. As LunarStandard said way back, a "point buy" system is best reserved for when you're actually playing out the duels with luck elements to them, as it ensures everyone is on a level playing field at all time. Here, you don't really need to be. There's no worry about consistency, only card choices, and you can worm yourself out of anything if you left enough options for yourself with a bit of extra elbow grease. Creative deckbuilding takes precedence over competetive, and I just want to encourage people to use really out-of-the-way stuff.
But yeah, if people want to pull packs I'll let 'em pull packs. Seems like there's two in favor of the idea already.