I'm just coming from watching your video on this, and being a big idea person I really wanted to share my thoughts with you because I'd love to see you take this game seriously. Firstly I'll throw out some very general design ideas that maybe you can toy with. Going off of your original idea to a deck where a player would get their cards at random, I thought it'd be neat if you sectioned all of the moves into four separate decks: A punch deck, kick deck, defense deck, and special deck. With this set up you could incorporate the typical Highs, Mediums, and Lows for the punches and kicks but you also open up a way to diversify each character and their movesets. Want like Cammie then you can simplify the punch deck, add more unique kicks, and add dashes into the defense deck. The hope is that this system makes building a roster easier as it could tackle the issues of differing movesets and playstyles.
Another thing from a gameplay perspective is if you can find a decent way to incorporate hitstun into the game (perhaps have each card show Stunned Turns with the others) then you might be able to set up a couple of different systems. The first one being that once a hit is landed then a card could be highlighted for an optimal follow-up? Of course the player wouldn't need to take it. The goal is for this to be a way to bring combos into the game and allow for players to find/create their own. Following the idea on the "optimal follow-up" maybe you could also have cards locked behind certain others or even a certain criteria being met. This is mainly where the special deck would come into play in my eyes. Say a character lands a high knee, uppercut, or super kick these actions could unlock a card from the special deck that could be used for a devastating follow-up. I'm hoping this along side the cooldown meter would help your more powerful special moves from being too overpowered as now a player can't just throw them out there anymore.
The last thing I'll talk about in this dump of text is actually ideas for characters and the roster. Power to you for using the characters from your WIP anime, but since I'm unaware if you want this game to be tied to it I thought I'd just throw something out there. With Chess being the inspiration for this game I thought it'd be neat to having characters and their movesets loosely based off the Chess pieces. It doesn't have to be anything major or on the nose like having characters named King and Queen, or anything like that. I think just the starting letter is fine. I think the best example of this would be the character based on Rook; their name could be something like Rockie or Roxanne, and they'd of course be a rushdown/grappler. Just something simple like that.
Anyway I just wanted to get these ideas to you while they were still fresh in my mind. I hope you enjoy them and can get at least some insight from them. Thank you for taking the time for reading all this, and most of all good luck in all of your endeavors!