That's fair, and moving forward, I wouldn't want to just return to that format either. I've spent a lot of time trying to crack the code to the perfect card system because it's just an almost impossible concept to do well in this game's format. Trying to create 6 cards that are both randomized, feature different effects that aren't a burden on the player to remember, and are also somehow perfectly balanced is just a nightmare. I have examples of concepts that I think do well enough, but each features its own flaws.
But one thing I try and think about in terms of ensuring its consistent loop is engaging at all levels is making it very set-up focused. I've brought it up before, but essentially, certain supportive GCD actions generate stars that orbit you that, when triggered, will detonate around the target of spells and weaponskills as additional, Malefic potency damage. You could apply an effect that allows you to trigger these for soloing, or pass them over to your teammates for them to detonate for you.
I've brought up before the idea of GCD cards where you still do a lot of weaving to pass these stars around, and I believe I recall you not liking cards on the GCD no matter what.
Lately, I've been wracking my brain around something a bit different, though it's a very nebulous concept at the moment. Basically, my head is circling around the idea that rather than drawing random cards, you have a "hand" like you would in a TCG of some sort, where each card is a one-use resource. You start with 3 random cards in your hand which would appear on your gauge, and those would enable specific actions. For example, maybe rather than playing the balance as its own effect, the balance is a token used to activate Divination, or something like that. You can draw back up to a max of 3 cards. Cards retain having a solar, lunar, or celestial affinity, and playing the new action "Reverse" swaps your current card with the other of the same affinity if it's still in your deck, and once one of your cards is used, that card is essentially in your discard pile. The idea here is you're meant to have 1 use of each card per "rotation" and the new action "Reshuffle" shuffles that back into your deck so you can use those resources again.
It sounds more complicated than it would be in practice I believe, but the actual specifics of how it mechanically works and what resources each card gives you isn't something I've been able to figure out yet. But conceptually, regardless of whether or not you had a party, these card actions would still be usable solo, even if granting you effects you don't necessarily need, and you can still earn these stars to detonate with your own Malefic casts.
Your direct offensive library would be very shallow, but because it's being supplemented with card playing and/or card-costing actions that generate stars, its a lot more varied. My headspace is in this general direction for your offensive library:
- Malefic stays as your filler
- Combust is replaced with an action that generates multiple stars on a GCD cooldown of 30 seconds with charges.
- Gravity's damage to your first target is the same as Malefic and is 50% less for remaining enemies, has a slightly higher MP cost, and also applies a 5% damage reduction debuff on your targets for 5 seconds, effectively merging it with the old Disable action and has you use Gravity in single target situations to respond to incoming attacks.
- Premonition is a new action that would have a lengthier cooldown, such as 2 minutes, and is a point-blank AoE spell that consumes all your current stars and puts a 3 second cooldown with a stack for each star consumed that works kind of like a reverse Haima, dealing damage and consuming the stack over and over until all stacks are consumed when its duration expires, and the next stack takes another 3 seconds.