I only tried the OP deck once and lost and since then I've simply returned to my first (unupped, without rares) FG farmer, liquid antimatter:
http://elementscommunity.org/forum/index.php/topic,17730I win regularly with this deck, mostly EMs, too. The only thing that can happen and will most probably cause a deckout is that Neptune doesn't play any dragons. You can win with 6 crawlers on which you use the combo (6x6x6= 216 damage), but chances are your last combo card is hidden at the bottom of your deck.
Very simple strategy with Neptune: Play the pendulums, ignore the Octupuses, keep the liquid shadows for later. Play your first antimatter on a crawler if he doesn't have any dragons out yet, the latter are always preferable, of course (antimatter = healing you for 13 instead of damaging you). Play a Dusk Mantle when you have the quanta, Neptune has no PC. Your HP will probably rise back to 100.
As always with liquid antimatter, calculate the damage you will cause once you've played both the combo cards. An arctic dragon runs at 13/5, which means 5 turns of hurting him 13 HP (only when previously antimattered, otherwise he'll heal himself), so 65 damage. Three dragons are not quite enough (195 damage), so you want four dragons or three dragons and one crawler or two dragons and two crawlers or one dragon and four crawlers. With Neptune, you can really wait with the liquid shadows until you are down to a few cards and then play all of them together.