I'm okay with shard of focus having synergy with gravity more so than any other element, so the gravity pull/overdrive/trebuchet thing is okay, but I think it has too much hp. Making it a permanent as was suggested makes it even more OP, because then there are even fewer ways to deal with the card, plus consider the mirror match; the first person to play shard of focus will keep the other player from playing one (or pulverizer) and thus negate two of the very few cards that could actually stop it if it were a permanent.
In regards to the comments comparing shard of focus with explosion, I'll put it this way. In any case where I can use shard of focus (i.e. not tourneys) I will use it over explosion, -including- in monofire. The power of shard of focus should not exceed an element card like that, yet it does. Even in decks that could use pulverizer, I'll often use shard of focus, because I can get the black hole, and obviously use it if I could've used pulvy.
Ideally, shard of focus should be comparable in power to something like butterfly effect. BE is the weakest form of PC currently ingame, and an other card accessible to any element should be among the weakest, not the best one.