Shard of Moderation: Limits the quanta production of the foe to 30/N per turn. N is the number of Shards of Moderation in play on your side +1 if your mark is gravity.
Mark of gravity:
Mark other than gravity:
Example 1: You have 2 SoM on your side and a mark of gravity. The opponent can produce maximum 10 quanta per turn. He has 3 quantum towers in play. He plays one more (3 quanta). At the end of his turn, his towers will only generate 7 random quanta (instead of 3x3=9) and no qantum will be produced by his mark.
Example 2: You have 2 SoM on your side and a mark of air. The opponent can produce maximum 15 quanta per turn. He has 2 fire towers in play. He plays a nova (12 quanta). At the end of his turn, his towers will generate 2 quanta and his mark 1 without alteration as he just reached the maximum allowed by your shards.
Example 3: You have 2 SoM on your side and a mark of air. The opponent can produce maximum 15 quanta per turn. He has 2 fire towers in play. He plays a supernova. From the 12x2=24 quanta expected only 15 picked randomely will be produced. At the end of his turn, his towers and mark won't produce any more quanta.
Example 4: You have 2 SoM on your side and a mark of air. The opponent can produce maximum 15 quanta per turn. He has 2 fire towers in play. He plays a supernova. From the 12x2=24 quanta expected only 15 picked randomely will be produced. Luckily, he can now play a deflagration on one of your shards which brings his maximum back to 30. The lost quanta from the supernova are still lost (too late man) but at the end of his turn, his towers will generate 2 quanta and his mark 1 without alteration as he didn't reach the maximum allowed by your shard.
The Shard of Moderation is obviously more efficient against rainbows than against other kind of deck. It is particularly efficient to counter spells which generates quanta (Nova or immolation). Please vote for the shard of moderation. Do not play with moderation ...
This is the shard I've seen so far that IMO has the best thematic relation to the gravity element -- I see Gravity as akin to order, or the grey center between the extremes. Moderation fits with that better than it would with any other element.
As for the mechanic itself, I love it. It's another denial card, a clever one at that, and it rewards people who use those in bulk. Though you didn't include those in your examples, I assume it blocks quanta produced from creatures as well as pillars. If that's the case, card order might be involved in an interesting way. Fire Queen, for example, would only be able to generate fire quanta against 6 SoM's, since her Fireflies go before pillars and take up the four spots allowed. You might be able to lock her down in terms of 
and 
if you play the combo early enough. Come to think of it, would it stop Devourers as well? Because the darkness quanta they generate technically come from yours, so if that's the case the SoM could be a mini-Sanctuary of sorts.
I didn't mention it but yes it also would count the quanta generated by the creatures. I think devourer should absorb 1 quantum each (this is not hindered by the shard) but produce quanta only up to the limit given. Thanks for the nice comment.
This is a unique idea and it fits Gravity. It can be a great card against rainbows and, unlike black hole, it is decent against monos and duos. The upgraded version is great because it seems like more quanta is generated in upgraded play. Supernova generates twice as much quanta as Nova, Cremation generates two more quanta than Immolation, and Towers generate one more quanta than pillars. I could imagine a Discord Black Hole deck becoming a lot stronger with a few of these. The Shard of Moderation could also work well in a deck with Precognitions and Reverse Times. The Precognitions would ensure that this card is drawn quickly, and Reverse Times are great denial cards in Time. Unlike the upgraded version, the unupgraded version doesn't seem worth using. It will take two Shards of Moderation in order for the denial effect to be useful, but even if there are six in a deck, it will be too late by the time two are played. The enemy will have a lot of quanta and still generate ten every turn. I think the unupgraded version should have its cost lowered.
You say that the upgraded version is much better because Supernova produce more quanta than nova? In fact, outside PvP1, you can use the unupgraded version against SN. The effects depends on what your opponent plays not what you play. The only difference is that the unupgraded version cost 1500 less electrum and 2 quanta more. Thanks for the nice comment.
Chat log of 1rst august:
[09:35:20] ~Napalm: Some of these Fire Shard submissions are just too powerful :S
[09:35:36] ~Napalm: All because of Cremation... because Cremation is OP...
[09:36:44] SnoWeb: ‹@~Napalm› may I quote you? ([09:35:36] ~Napalm: All because of Cremation... because Cremation is OP...)
[09:41:32] ~Napalm: lol Snow
[09:41:35] ~Napalm: Go for it.
