I like the concept, but I don't think darkness needs an extra quanta production boost. It already has devourer for that.
The elements that don't have non-pillar production are:
I think the game needs a rustler like card for one of those first before adding more to elements that already have alternate sources.
Aether doesnt need it, Entropy has Nova. Gravity has Black Hole, which is the opposite, but still applicable. I do think other element could use alternate Quanta generation, but Im focusing on this one dynamic right now.
Ah. Now you want synergy with immo. Sure let's look at that.
3 cards + 1 turn = 17 
+ 10 
. Is this balanced?
Explain why out of the 132 rustlers that 
--> 
ones are needed and if they are balanced with cremation or not.
I would like to see some play test results.
Im not really concerned with the other elements, I think other quanta generators and boosters would serve many elements well.
I do think the dynamic is balanced overall, as it is a one time use, consider SNova, with +22 Quanta for one card, or Nova with 12 for one card. 27~ for 3 cards is pretty balanced by the look of things. Im looking at things from primarily a thematic view, and Darkness is a traditional force that gets strong energy boosts from card play. Consider M:tG Dark Ritual, the first common mana producer, with one black to 3 black for a net gain of 2. other than ultra rare Mox's and the Lotus, this was predominant. I am creating a similar card here. It is long standing that 'dark magic' gets boosts to energy production by sacrificing something else. In this case, you are burning something and using the fire to create dark energy, by empowering the ritual. One might think of it as incense or smoke that puts one in a trance, or the movement of the flames, I just think they go together well. You could also say that fire makes smoke, thus creating a cover of darkness.
Balance wise, if you look at other combos, 3 cards to play a dragon is pretty balanced overall, given that its only one and cant do much else. Look at fire, which for 4 cards can play a dragon and a weapon, shield, phoenix or golem. Cremx2+RoLx2
You could also look at Entropy, with 3 cards, an upped pillar, a ray of light and improved mutation for a possible dragon or other powerful creature. How about Nova + SoFo? Pretty nasty overall.
Looking at the metagame, the overall distribution of force, Darkness has its power, but it has waned of late. Time is very powerful with SoR, Pharoah, etc. Air has Sky Blitz and SoFr. Light has Sanctuary and Crusaders, making it quite formidable. Darkness is weak. Giving it a solid combo to produce large amounts of quanta, enough that Drain Life starts doing as much as shockwave, or to summon a dragon, would serve it well. Elements is all about combining power. Dark Rites is strong on its own, maximizing Quanta production, Using it in combination with Cremation, i.e., giving a living sacrifice to it in conjunction creates a logical, thematic and quite balanced play.
Consider the deck:
6: Dark Rites
6: Cremation
6: Ray of Light
6: Obsidian Dragon
6: Cloak or other cards of your choice, EA, Purify, a shield come to mind. Shard of Bravery would be a solid choice.
this is a minimal 30 card deck and roughly gives the core of its use, without much frills. Its the most direct application of the card. Now compare it to Instosis. Instosis can be used to OtK, this cant. Instosis can pump dragons for free turn after turn, this cant, only 6. This is faster, but can be broken with permanent control. So when you put it up against another existing, strong dragon summoner, its different, but not more powerful.
All in all I think it makes a nice addition to the game and combines two elements without much current synergy. Fire and Darkness go hand in Hand, this card brings them together in the game, where there is little if any connection between them.
Personally, I think this could be used the turn it is cast without breaking things, or possibly as spell that simply converts your fire to 2x Darkness quanta.
