At a rough glance, it looks like we can build a ghostal (or two), a poison dial, a novabow (or two), a light stall (or two), and maybe some silly time/death deck. (though obviously not all of those at once)
For my match vs earth, I would prefer to use a novabow. The decks they've been beating us with are earth/air wings and earth/gravity pulverizer, and novabow with pulverizer. If I had a darkness mark, we salvaged the steals/nightmare from death, and I had the two explosions in my deck, I think I could handle any of those. The problem with that is that it uses ALL our pc in the vault, leaving none for anybody else on the team. However, I'm not sure what other decks we can build that would even use the pc. Playing the dark mark would also let me use lycanthrope and nightmare(s), and maybe even some other dark cards if we salvaged them from the death/dark deck, though I doubt I'd use any of the other ones there. (dusk is good and should probably be salvaged, but I'd rather play fog in novabow) I think I could build a pretty good one, although with a dark mark I wouldn't be able to use more than one graboid at most, so I'd have to use more pillars and some time creatures if I did that.
edit: I think I just had a better idea. Instead of dark mark, use earth mark. I could still use 2 explosion 1x upped steal and then I could use 3 upped graboids which would take 2 hits to kill with EE. (meaning I could burrow it in time) I could use the unupped ones as well, though they're more vulnerable to EE. I'd be harder pressed to squeeze in the lycan or nightmare, but one of them might be possible alongside the steal. I'd also like to have 1 or 2 more pillar/pends than I had the last time I played a novabow; quanta was pretty tight there some games.
