I have two solutions for Sparks of Life. The first, and honestly the easier route, is to make Sparks of Life drop more frequently on the normal difficulty, and drop rarely on the elite difficulty.

The other is to add a new rarity called a "Life Essence". These allow you to revive a teammate by walking over their body and attacking twice, like old health revives. These will restore full red health (up to 30 pips). They cannot be used to revive yourself.
Make these drop frequently, and make sparks of life rarer. At that point it puts a lot of emphasis on difficult missions being played in teams as you'll have significantly more Life Essences than Sparks of Life.

Would it be worth it/too late to necro this thread to add my two cents?

I think it's very important that we reexamine the core problems with Rarities themselves, because without exaggerating, Rarities are the worst thing to have ever happened to Spiral Knights and have ruined the endgame for many people.

Orbs of Alchemy and the removal of pay-to-play elevators were the last nail in the coffin for the Energy Market, because, surprise, that's what happens when you cut out the main two reasons most people bought and traded Crystal Energy. Sparks of Life? They turned reviving a teammate, originally an act of courtesy that required self-sacrifice, into a commodity, because who would want to just give a Spark away for free to someone they just met?

But the overarching problem that Rarities created was how they killed the pacing of the game. Sparks of Life did this by removing any sort of penalty for dying many times. The game is now more pay2win than ever as you can make as many mistakes as you want and still win.

How about Fire Crystals, or rather, let's place several weeks' worth of grinding and luck at the end of a task as simple as heating your piece of gear to the next level.

Dropping money on the game to buy your way through the Forging process isn't even worth it. Twenty bucks might be enough to heat one five star weapon to Level 10 if you don't get bad luck, compared to the five dollars it would have taken to get CE for crafting in old SK. If I chose to buy Fire Crystals to Forge just three weapons, I'd be set back by almost as much as a brand new game would cost me.

Now, why do I mention all this? Because I don't see how the solution proposed in this thread is anything more than a marginal improvement of these problems, as it's only simplifying the broken process. The Energy Market would still keep falling, purchasing Energy would still barely speed things up, Sparks of Life would continue to break the game, and the pacing would still be utterly broken. Not to mention, wouldn't I be completely starved for Fire Crystals by the time I needed to heat my five star gear, if I was using all of them on my 4 star stuff?

I have a different solution, an evolution of the old system that still retains familiarities from the modern system to keep people from being confused and requiring reimbursement for all of their Rarities when they're dummied out.

My proposed model

I will be borrowing a few elements of this post as I find them to go hand-in-hand with my solution.

Okay, first is a big change to how Rarities are acquired. Orbs of Alchemy no longer drop in Clockwork levels, they can only be acquired from the Depot or opening Prize Boxes. Sparks of Life and Fire Crystals still drop but more rarely than ever before. These changes are solely made to help stimulate the Energy Market again and give people a reason to pay real money that isn't premium content. Fire Crystal prices on the Supply Depot would be adjusted to be more reasonable and balance with the other changes.

The second change is to increase the Spark of Life requirement for each time you consecutively revive. Revive once, you need 2 Sparks next time. Revive twice, you need 4 Sparks, three times and you need 7, you get the idea. Remember these numbers are just placeholders and not to be taken literally.

The third change is an overhaul of the Forge. First, let's go over how Heat would be dropped. Every monster drops different colored embers based on their family and damage type; grey embers for Constructs, dark red for Normal damage, purple for Shadow, etc. Monster family embers are absorbed only into weapons and damage type only into armors and shields. When you open the Forge and check the gear, you can see how much of each color you've collected, with a Total Heat meter at the bottom, which you need a certain amount of to be ready to Forge.

This ultimately factors into how Unique Variants are acquired in the new Forging and crafting process.

Fire Crystals are now craftable with the new Spark Shard material. Spark Shards are granted in set amounts at the end of each level, with a small chance to get a few extras. The amount you get is different for each level, and is always changing. Meaning, some days Vanaduke might give a generous payout of Shards, other days you will be better off in an Arena or Aurora Isles to get your fix. Obviously, the higher level crystals take more shards to craft.

Every type of Fire Crystal is crafted from this material, but you will almost always get far greater payouts the closer you are to the Core; therefore, Dreams and Nightmares will be one of the highest paying levels basically every day.

The Forge itself no longer has the minimum, medium and maximum options. These are respectively replaced by the Standard Forge, Overheat, and Meltdown. Standard gives you the best odds for a successful forge and requires the least amount of crystals, somewhere in-between the current minimum and medium options. Overheat, on the other hand, feeds more crystals into the machine and offers a small chance of heat bonus, double level up, a lower-level Forge Prize Box and a weaker unique variant (more on this in a minute). The Overheat option has the biggest risk of failure and feeds even more crystals in, giving a better chance for the aforementioned bonuses including a higher-end Prize Box and slightly better UVs.

Finally, we come to unique variants. Monster family and damage type (NOT status, CTR or ASI in other words) can be offered now simply by forging a piece of gear. Depending on how much Heat you have built up in particular areas, you have a greater chance of getting the corresponding UV. In other words, your gear learns from which enemies you fight the most often, in turn having a chance of giving you an advantage against those enemies. As said before, you have greater chances of this happening if you use more Fire Crystals.

I think this system works better because it removes luck from the equation almost entirely if you just want to level up your gear without anything fancy. The pacing is improved since you're getting a constant supply of Heat and Fire Crystals simply by playing the game as you see fit, not by relying on luck of the draw and having to play levels with tons of red Treasure Boxes to have a chance of getting more Rarities.

All I hope is that Grey Havens implements something that we can enjoy and will make them more money, because the current system seems to be accomplishing neither of those things. Personally, I think the ultimate answer is to just bring back Mist, elevator fees and passes, but I've yet to meet a player who agrees...