Heh, I'm aware I mostly post when I'm not happy, but this is really a topic I don't want to miss.
This is yet another shard I despise. In my opinion, the last two updates - especially with the introduction of the (now slightly nerfed) SoSa and SoFo - changed the entire game and broke it, to the point where I almost completely stopped playing since war. It used to be Elements, but it is hardly more than shardements now, it's really all about having and spamming SoFo which is splashed into just about any deck in arena or pvp. More often than not, you face a turn 1 SoFo followed by many others, and the previous nerf hasn't changed anything in my opinion. There will of course always be those who don't have a problem with anything because they're so incredibly pro that they'll just "CC it away", but my point is that the entire game has shifted towards "anti-SoFo" decks, just the way it was before with SoSa, and that doesn't help keeping the game varied but makes it just boring.
Now that I expressed my disdain of the recent evolution of Elements, I might as well try to make some suggestions to improve this.
Not sure raising the cost even more would make a big difference. Right now, 2 Quantum pillars are enough to play SoFo on turn 1, even with raised cost, it would probably not take more than 3 Quantum pillars to do so.
One suggestion would be to let it use its ability only once before turning into a BH, that would limit it to a max of 12 perm destructions even in an arena deck with doubled card amount.
I also like the idea of giving the ability a cost (

Quantum preferably) equal to the cost of an Explosion/Deflagration, depending if the Shard is upped or not. Playing the Shard would still cost random Quanta but actually using it would require to at least have some

Quanta in your deck.
The third option - by far my favourite - would be to remove all those bloody Shards and create more cards for each element, making the game more varied, balanced, and therefore more interesting.